Hi @RedivaDantes, nice to have you onboard. We dont have a specific method for importing from these external systems, however you can:
Export your notes from Google Keep as text files and import them as markdown:
Export your notes from OneNote as docx, preprocess/convert them using something like pandoc and import as markdown:
Lastly, reading the Transno website it looks like they support Freemind or OPML exports, so you can convert those to markdown as well:
I’m really sorry this process is so complicated, I know how much of a pain it can be to migrate your data around from system to system from personal experience. Hopefully Anytype fits your needs for a while so you dont have to go through the process again.