If you mean how to submit a manuscript to ResearchGate, so please note that ResearchGate is not a publisher, you cannot publish a paper here. It is a platform for papers published in journals, or to present unpublished texts, data etc. See also "Is ResearchGate a publisher?" in https://help.researchgate.net/hc/en-us/articles/14292596164753. And see this help page ("How to add research") for instructions how to add published or unpublished research to ResearchGate: https://help.researchgate.net/hc/en-us/articles/14293005132305-How-to-add-research

If you mean how to submit to a journal, see the "Instructions for authors" or something like this of that journal, and see also these previous discussions:

https://www.researchgate.net/post/What_are_the_procedures_for_publishing_a_research_paper/1

https://www.researchgate.net/post/For_publishing_article_in_any_journal_which_necessary_steps_should_be_taken_care_by_a_new_researcher/1

You should decide which journal you want to publish in then check whether its scope matches your manuscript topic or not. If yes, read their guidelines and modify your manuscript structure and citation style according to it then create account and follow the instruction of the required documents needed to submit your manuscript.

Thank you

Nourhan Moustafa El-Sherbiny