open the site then press (Ctrl+Shift+i) then from the right panel that appear choose (Source)
you gonna see the theme name as the photo says:
if it's Donut Theme, I found the repository to download.
The site with the running theme.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
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July 25th, 2023: Q2A 1.8.8 released!