Trigger in Google Script on short script, based on an IMPORTRANGE function from another sheet (onEdit does not work here)

I would need help in these two scripts: 1. The script basically should delete a row if a cell contains a certain keyword in a specific cell of the same row. This would not have to be done onEdit, but on the change of the sheet. Basically, the information is imported via an =IMPORTRANGE function in another Sheet. Thus the change should come from the change transcribed from the imported data (the change that is made in the other sheet). 2. I have a script, where I want to do a similar manoeuvre, basically set it off based on a change that is transcribed via an IMPORTRANGE function, where the change, here too, happens in the other sheet.