Problem with uploading file Angular and Flask

First of all excuse me if it's not well explained but I'll try my best. I'm trying to upload files from my front(Angular) and I'm having troubles with it. so far, this is my Service:

export class FileManagerService
{
    file: File = null;

    baseUrl: string = 'http://127.0.0.1:5000/';
    public addFile(file: File) {
            const formParams = new FormData();
            formParams.append('file', file.data);
            return this._httpClient.post(this.baseUrl + 'upload', formParams);
    
        }

}

this is my component.ts :

onFilechange(event: any) {
        console.log(event.target.files[0]);
        this.file = event.target.files[0];
    }


    upload() {
        if (this.file) {
            this._fileManagerService.addFile(this.file).subscribe((resp) => {
            alert('Uploaded');
            });
        } else {
            alert('Please select a file first');
        }
        }

and this my component.html

<div class="mt-4 sm:mt-0">
                <!-- Upload button -->
                <button (click)="this.upload()"
                (change)="this.onFilechange($event)"
                type="file" id="formFile"
                    mat-flat-button
                    [color]="'primary'">
                    <mat-icon [svgIcon]="'heroicons_outline:plus'"></mat-icon>
                    <span class="ml-2 mr-1">Upload file</span></button>
                    <input (change)="this.onFilechange($event)" class="form-control" type="file" id="formFile">
</div>

okay so when I try uploading a file I get in my console BAD REQUEST and the file is undefined any help would be much appreciated, thank you!