Commander X16

I read somewhere that ACME assembler was the assembler of choice for the Commander X16, but when I compile my code (windows) using this command:

acme -o program.prg --cpu 65c02 program.asm

It reports that the STP command is a label.

I want to use the debugger, but I can't if I can't assemble with the stp opcode.

Maybe there's some custom version of the assembler I don't know about for the cx16? Should I just go back to ca65?

I have the same issue with both Acme and CA65.

Usually, I just do
!byte $db ;for acme
.byte $db ;for ca65

I can't speak for ACME, but CA65 supposedly supports the STP mnemonic, as long as you've properly set the processor as 65C02 (not to be confused with 65SC02, which doesn't support it).

Just found that Acme also supports the stp and wai opcodes, you just need to set the cpu correctly.

!cpu w65c02