Buy the manga

Is it available in English in any site to be bought

Good for you, showing interest in supporting the author! Unfortunately I don't believe there's an official english version. It's still really really new after all (It came out in March 2020).

You can buy the Japanese version here though: https://www.amazon.co.jp/dp/4758020957
or here through Renta (JP): https://renta.papy.co.jp/renta/sc/frm/item/209164/
There are some other websites (like bookreader or cmoa etc.) that also sell the book and if you search the Japanese title listed under the 'Alternative' titles you should be able to find them.

Here's the author's twitter in case you want to keep up with the latest news: https://twitter.com/nmuranmu

Thank you. I like to support my fav authors even if I can’t buy all their books