using gpgsm to sign a file

for X.509 certificates. we can use gpgsm to sign a file using the option --detach-sign.
this will create a separate signature file that can be verified on the other end.

how to make the signature in the same file using gpgsm?

I used the option --sign. I could virify but I could not decrypt.

the idea is to encrypt file and sign it and on the other end verify the file and decrypt it.