Just like willman said, use a script like the one below will clear all files in recycle bin.
$userCredential = Get-Credential -UserName $adminUPN -Message "Type the password."
Connect-PnPOnline -Url <https://tenant-my.sharepoint.com/personal/username account> -Credentials $userCredential
Clear-PnPRecycleBinItem -All -force
Clear-PnPRecycleBinItem with the Identity parameter set will delete a single specific item from the recycle bin (documentation here), and the -All parameter will delete all the items in the current site collection's recycle bin.
So assuming your script is running under a user account with the correct privileges, it should be able to connect-pnponline with ...