How to submit a membership request to sharepoint

Hi everybody, 

ladies from HR shared folder on sharepoint site with me where are some excel files which I need to use in flow. The question is how to submit to be a membership in this site? I can't find any specific button or options. I need use this site in flow, but I can't find it in flow because I suppose I'm not a member. 
Below I paste a screenshot of this site. I will be very grateful for all advices.