How to save a pdf from ID to upload to Amazon KDP without get the LaTeX/pdfTeX error?

I’m saving 175 inside pages in InDesign of a novel to be uplaoded to Amazon KDP, as a HD pdf using the default ID settings. After multiple errors uploading, they said the issue was that hey don’t support a LaTeX/pdfTeX formatted pdf. I’ve never heard of that, but would like to know if I can adjusst that in the settings before saving the pdf. They said they prefer PDF/X-1a formatted pdf.