Got the script to work the first time. These errors caused it to crash

[7zed]

Fix: onlyfans - file_directory_format is a invalid format since it has no unique identifiers. Use any from this list {media_id},{username}
Fix: metadata_directory_format is a invalid format since it has no unique identifiers. Use any from this list {username}
Fix: starsavn - file_directory_format is a invalid format since it has no unique identifiers. Use any from this list {media_id},{username}
Fix: metadata_directory_format is a invalid format since it has no unique identifiers. Use any from this list {username}

[M-rcus]

The placeholder values are supposed to be put as-is, not "renamed". Based on your screenshot I suggest the following:

"file_directory_format": "{site_name}/{username}/{api_type}/{media_type}",
"metadata_directory_format": "{site_name}/{username}/Metadata",

Keep in mind that you're also editing the starsavn config, not the one for onlyfans (they are separate). My examples should work for both though.