Hi @PeggyLang
Instead of updating the link on your webpart I would have the webpart link to a file in a different document library with a generic name that won't change name e.g. homepageimage.jpg
The flow would be triggered on upload of a new file in the document library (when a file is created)
then get the file content of the image
next delete the existing homepageimage.jpg file
next create a file in the location and with name of your homepageimage file
Hope this helps, please mark as a solution if it does.
