Amending a nonfiler form. How does it apply to 1040X?

Filed nonfiler for 2019, however I now realize I need to amend my return due to needing to claim my child via paper (ex-husband wrongly claimed child on his taxes prior to me filing mine).

Everything I have found about filing the 1040X relates to someone who filed 1040(or similar). Because I didn't file those forms, is the 1040X still the correct form? Has anyone gone through this before?