Hi Ann,
That message (“The link you followed has expired”) usually happens when the upload limit / timeout on the server is too low for the theme .zip.
Fix options (try in this order):
Upload via FTP / File Manager (recommended)
Unzip the theme on your PC
Upload the theme folder to: wp-content/themes/
Then go to Appearance → Themes and activate it
Increase server upload limits
Ask your host to increase:
upload_max_filesize
post_max_size
max_execution_time
memory_limit
Then try uploading again from Appearance → Themes → Add New → Upload Theme.
Make sure you’re uploading the correct ZIP
Upload the installable theme zip (e.g. pokatheme.zip) — not the full “package” zip you downloaded (which often contains docs, child theme, plugins, etc.).
If you still can’t upload, please email support with a screenshot of the error + your current values for Site Health → Info → Server (PHP memory limit, max upload size, etc.), and we’ll tell you exactly what needs changing.