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:
https://ansbangla.com is my site
contact : Habibur Rahman
if it's Donut Theme, I found the repository to download.
The site with the running theme.
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May 7, 2020: Q2A 1.8.4 released!