Which form to submit for s-corporation amended 2018 return

[cookiegal]

I have a scorporation and need to file an amended 2018 return. Should the form I submit be 1120S with the amendments marked with line H "amended return" or do I need to submit a 1120X form instead?

[MaryK4]

The amended 1120S is the same as the original except with the Line H checked- there is not a separate 1120S-X like for individual tax returns.