It looks like it was an RPO with the RG pulling to block for the run. Josh decided to pull it and hit the post.
Morse wasn't on time to shift right to block the first man rushing through the RG's evaded hole.
In any event, this play is a good example of why you don't zero blitz Josh Allen (any more.) They left Diggs one on one and Josh hits him for an easy TD even though the Dolphins rushed 2 more men than the Bills had blockers.