I’m trying to access the files within my Google Drive folder. I have the folder ID and using the following lines of code, but the folder returned is empty

    var folderid = '1R07zv6TK9ka_BX--EMucP4pFlqYUsDJH';
    var folder = DriveApp.getFolderById(folderid);
    var files = folder.getFiles();

What would cause the getFolderById method to return null when the folderid is correct and I have access to said folder?

The folder ID is correct and it is a folder in My Drive

Folder ID in Google Drive