Replace multiple statements

This has already been answered and I wouldn't recommend this version (linters probably complain, flat if statements are fine) but I'm throwing it in there to show another possibility.

You can potentially use a switch statement and add your conditions to each case:

const CONDITION1 = 1 > 2
const CONDITION2 = 2 < 1

const run = () => {
  switch(true) { // always evaluate this switch
    case !CONDITION1: 
      return 'STOP IN CONDITION1'
    case !CONDITION2:
      return 'STOP IN CONDITION1'
    // etc...
  }
}

console.log(run())

Using Array.prototype.findIndex()

• Store your conditions into Array
• Use Array.prototype.findIndex(). Just return the argument itself (x) => x, it fill be treated as boolean and if true the method will return the index. Store the returned integer into a variable errIndex.
• If errIndex is greater than -1 that means you have an "error" in the conditions array at that index

const conditions = [false, false, true, false, false];

const errIndex = conditions.findIndex(x => x);

if (errIndex > -1) {
  console.log(`STOP IN CONDITION ${errIndex + 1}`);
} else {
  console.log("All passed");
}

The nice thing about using .findIndex() is in that it can short-circuit the search and immediately return the index.

Not sure why, but given you want to return a String, and since return statements are used within a function, and since it's always preferable for a function to return the same type,
you could create a function that accepts an array of conditions and a success string as the second argument:

const status = (conditions, successMsg) => {
  const idx = conditions.findIndex(x=>x);
  return idx < 0 ? successMsg : `STOP IN CONDITION ${idx+1}`;
};

console.log(status([false, false, true, false, false], "OK"));  // STOP IN CONDITION 3
console.log(status([false, false, false, false, false], "OK")); // OK

or you can create something similar based on the above idea, like a pass function in which you do not hardcode error strings, but instead it provides you with a callback function with argument being an Object with index property or null

const pass = (conditions, fn) => {
  const index = conditions.findIndex(x => x);
  fn(index < 0 ? null : {index});
};


pass([false, false, true, false, false], (err) => {
  if (err) {
    console.log(`STOP IN CONDITION ${err.index + 1}`)
    return; // Exit function here
  }
  // All OK...
  console.log("All OK! Do some work here");
});