I am trying to create a solution where I can get all items in a list and then delete them using Microsoft Flow. For automating this process, we want to use a list that has fields for Site Url and List Title. I intend to use these values in the 'Get Items' action to get all the items. But when I use these dynamic values in the action, I get a Bad Request error about the SharePoint Site Address being not valid when I know that url is valid. The exact error message I get is below:

Any help is appreciated.
Thanks