missing file: post-smtp-hooks.js

I installed PostSMTP v2.0.5. I keep getting the following errors in my nginx logs:
2019/10/03 13:08:51 [error] 22615#22615: *23967 open() “/var/www/domain.com/wp-content/plugins/post-smtp/script/post-smtp-hooks.js” failed (2: No such file or directory), request: “GET /wp-content/plugins/post-smtp/script/post-smtp-hooks.js?ver=5.2.3 HTTP/2.0”,

This file is referred to from within postman-smtp.php, but it does not exist in the script directory