WP Add Mime Types
The plugin additionally allows the mime types and file extensions to WordPress. In other words, your WordPress site can upload various file extensions.
Please install this plugin and activate it.
If you use a language except English, please update the translation data in the updates of Dashboard.
If the multisite is enabled, please check the setting menu in the network administrator.
First of all, please check the “Media Type Settings” in the “Settings”.
You can see the list of allowed mime types and file extensions by WordPress.
When you add the mime type or file extension, the data will be added to last item in this list at the red color.
About the mime type list, please see the list of mime types in the information of the Internet.
The user who have the manage_options permission can only add the setting.
If you would like to translate it to your language, please visit the GlotPress from https://wordpress.org/plugins/wp-add-mime-types/ .
If the multisite is enabled, the multisite network administrator can add/change/delete the mime type value in the multisite network setting menu. And the multisite network administrator or the site administrator can only see the past value (cannot change) before the site was migrated to the multisite.