Change attribute dynamically angular from Json

I am trying to change the [icon]="ractAtom" to use a value from Json but it does not seem to work. Please, could someone help with this. In other words, the [icon]'s value should be based on the 'featureItem' that is being received from the parent

HTML

<div>
    <fa-icon [icon]="reactAtom" class="icon-automation"></fa-icon>
    <h3>{{featureItem.name}}</h3>
    <p class="card-title-features">{{featureItem.description}}</p>
    <hr class="line-separator">
    <accordion closeOthers="true" *ngFor="let accGroup of featureItem.accorditions">
        <accordion-group [isOpen]="false" #accordionGroupRef>
            <span accordion-heading style="display:flex;justify-content:space-between;align-items:center">
                <div>
                    <fa-icon [icon]="heart"></fa-icon> <span class="card-title-accordtion">{{accGroup.accorditionTitle}}</span>
                </div>
                <fa-icon *ngIf="accordionGroupRef.isOpen" [icon]="caretDown"></fa-icon>
                <fa-icon *ngIf="!accordionGroupRef.isOpen" [icon]="caretUp"></fa-icon>
            </span>
            <p>{{accGroup.accordtitionDescription}}</p>
        </accordion-group>
    </accordion>
</div>

TS

import { Component, Input, OnInit } from '@angular/core';
import {faReact} from '@fortawesome/free-brands-svg-icons';
import {faPeopleGroup, faBullseye, faHeart,faCaretUp, faCaretDown} from '@fortawesome/free-solid-svg-icons';

@Component({
  selector: 'app-features-item',
  templateUrl: './features-item.component.html',
  styleUrls: ['./features-item.component.scss']
})
export class FeaturesItemComponent implements OnInit {
  @Input() featureItem:any;
  
  reactAtom = faReact;
  peopleGroup = faPeopleGroup;
  bullseye = faBullseye;
  heart = faHeart;
  caretDown = faCaretDown;
  caretUp = faCaretUp;

  constructor() { }

  ngOnInit(): void {
  }

}

Here is the JSON that I am using:

featuresJson = [
      {
        "name":"Automation",
        "mainIcon":"reactAtom",
        "mainIconClass":"icon-automation",
        "description": "Automate admin work and cut costs by 60%",
        "accorditions":[
          {"icon":"heart",
            "accorditionTitle":"Complience",
            "accordtitionDescription":"Certify employees on the latest policy and regulatory requirements."
          },
          {"icon":"heart",
            "accorditionTitle":"HCM Sync",
            "accordtitionDescription":"Streamline the learning experience for employees and administrators."
          },
          {"icon":"heart",
            "accorditionTitle":"Live",
            "accordtitionDescription":"Schedule training sessions, increase fill rates & verify attendance digitally."
          }
        ]
      },
      {
        "name":"Enablement",
        "mainIcon":"peopleGroup",
        "mainIconClass":"icon-enablement",
        "description": "Enable client-facing teams to over perform",
        "accorditions":[
          {"icon":"heart",
            "accorditionTitle":"Mobile Advanced",
            "accordtitionDescription":"Provide frontline teams with shared device access, video evaluation & mobile content creation."
          },
          {"icon":"heart",
            "accorditionTitle":"Coaching",
            "accordtitionDescription":"Boost confidence and performance through Coaching."
          },
          {"icon":"heart",
            "accorditionTitle":"Extended Enterprise",
            "accordtitionDescription":"Onboard new clients, partners & other non-employees in your 360Learning environment."
          },
          {"icon":"heart",
            "accorditionTitle":"Software Adoption",
            "accordtitionDescription":"Turn your team into tool experts with interactive training experiences."
          }
        ]
      },
      {
        "name":"Development",
        "mainIcon":"bullseye",
        "mainIconClass":"icon-development",
        "description": "Make professional growth a pillar of your company's culture",
        "accorditions":[
          {"icon":"heart",
            "accorditionTitle":"Onboarding",
            "accordtitionDescription":"Make sure new employees hit the ground running and ramp-up quickly."
          },
          {"icon":"heart",
            "accorditionTitle":"Curated Programs",
            "accordtitionDescription":"Give learners access to catalogs of best-in-class courses."
          }
        ]
      }
    ]

So, I was trying to do the following but it would simply not work. I'd appreciate any input.

<fa-icon [icon]="[featureItem.mainIcon]" class="icon-automation"></fa-icon>