How to properly configure .htaccess with redirect with id?

Question

htaccess

Explain page:

domen.ru/page?id=123 должна перейти в domen.ru/page123

It turns out to be done with:
RewriteRule ^page/(.*)?$ page.php?id=$1 [L]
But then the page will be domen.ru/page/123, i.e. with a slash before id.
If you do
RewriteRule ^page(.*)?$ page.php?id=$1 [L]
that, it stops working altogether.

Answer 1

I tried for a long time, asked a question - I immediately found the answer.
RewriteRule ^page([0-9]+)?$ page.php?id=$1 [L]