“I am sorry, you can only upload image files in the formats .GIF, .JPG, .PNG, .WEBP, .SVG”
Please provide a screenshot of the WordPress dashboard screen showing this specific error message. Be sure to show the URL in the address bar (especially everything after/wp-admin/), as well as the active dashboard menu item (left navigation column).
There’s something on your site or server that’s restricting the types of files that can be uploaded. This could be a WordPress security plugin (more likely), or server configuration restricting such uploads.
Do you have any security-related plugin that could be restricting allowable files? If you’re not sure, a simple way to find out is to disable ALL plugins and try to upload the plugin file.
Alternatively, you could unpack the plugin’s zip file and upload the folder via FTP to /wp-content/plugins/.