This message shows because your upload limit is less than theme size.

You need to change this PHP value (server value) upload_max_filesize in PHP.ini to at least 10MB

Your options are:

1. Increase max upload size via hosting (with hosting support help or by modifying your php.ini)

1. Locate the php.ini file inside the wp-admin directory (if you can’t find this file ask hosting for support)
2. Find this line in the php.ini file “upload_max_filesize = 2M” and replace it with a higher value (e.g. “upload_max_filesize = 64M”)
3. You may also want to increase your max post size. Look for this line in your php.ini file “post_max_size” and increase it as well.
4. Save the changes to the file inside your wp-admin directory.
5. Try the upload again
6. If you still have issues, look for this file in your root directory and make the same changes.

2. Add the theme or plugin – via FTP

See also https://help.wprentals.org/article/how-to-update-the-theme-and-plugins/

or

https://help.wprentals.org/article/theme-installation/