Manual:$wgEnableAsyncUploadsByURL

Files and file uploads: $wgEnableAsyncUploadsByURL
Enable the async processing of upload by url in Special:Upload.
Introduced in version:	1.42.0 (Gerrit change 1007344; git #cfa7ed13)
Removed in version:	still in use
Allowed values:	Unspecified
Default value:	false
Other settings: Alphabetical | By function

Details

Enable the async processing of upload by url in Special:Upload. Only works if $wgEnableAsyncUploads is also enabled.