This is what appears:
JQMIGRATE: Migrate is installed, version 1.4.1
/wp-json/buttonizer/…?nonce=c4e8ea5857:1 Failed to load resource: the server responded with a status of 404 (Not Found)
dashboard.min.js?v=7…82e461&ver=5.4.2:87 Error: Request failed with status code 404
at e.exports (dashboard.min.js?v=7…82e461&ver=5.4.2:55)
at e.exports (dashboard.min.js?v=7…82e461&ver=5.4.2:55)
at XMLHttpRequest.p.onreadystatechange (dashboard.min.js?v=7…82e461&ver=5.4.2:55)
at XMLHttpRequest.r (dashboard.min.js?v=7…82e461&ver=5.4.2:87)