"at the end of the decryption" condition inside a function to return the decrypted text ?

hello everyone, I'm trying to create a function called decrypt, but I would like the function to only return a string, when all conditions are successfully satisfied...

like below :

is there any way to do this?

Decryption is an asynchronous operation, which means that it can take some time to complete. Other events will continue running during this time.

You can use "Wait for previous action to complete" action inside the function and change the function type to asynchronous, but it won't work with functions which return values.

Is there any way to do this in javascript?