A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Dear respected,
Good day. Welcome to Microsoft Community.
For the first demand, since it is related to SharePoint API endpoint, I suggest you post your concern in the related community: Questions - Microsoft Q&A with SharePoint Developmenttag to get the detailed help from the experts there.
For the second demand, kindly post in the related community:
Microsoft Power Automate Community - Power Platform Community
Few threads I found in there:
Solved: SharePoint search api - Power Platform Community (microsoft.com)
Solved: REST API and SharePoint Search - Power Platform Community (microsoft.com)
Apologies for redirecting you to a different community as the community moderators in the category mainly focus on the out-of-the-box features in SharePoint Online platform and have limited knowledge on the customization or SharePoint API endpoint and Power Automate flow building, so to get the fast and better assistance for you and your organization, we have redirected you to the correct community.
In addition, I will keep this thread open so that SharePoint MVPs in this community may share their ideas and other possible troubleshooting suggestions on your scenario.
Thanks for your time and effort on checking my reply above. Appreciate your patience and understanding. Have a great day!!
Best Regards,
Mia