1️⃣ - They have asked for a cover letter -> Send a cover letter ✅
2️⃣ - They've said, 'cover letter is optional' -> Send a cover letter ✅
3️⃣ - They've said, 'send your resume only' -> Don't send a cover letter ❌
Ok, I appreciate this seems simple enough, but I speak often with hiring managers who consistently say that their first cull of applicants is when the candidate doesn't do what has been asked for in the job advert.
You'd be amazed at how many applicants get this simple step wrong.
If you need help writing your awesome cover letter, get in touch - firstname.lastname@example.org