C-SP-315 not compatible with 3/4 HP Craftsman Garage Door Opener

Asstated, our C-SP-315 remotes are not linking up with the 3/4 Craftsman Garage opener. I have tried all butons (A-D) and none work. Please advise

Hi David,
Sorry for the trouble, would you please send me your opener’s model number?
So I can check, thanks.