Can I keep all my pages in two languages ​​in the same (root) folder? (not much choice)


Hi,

I use Bubble for my website, a Nocode product. I love it, but let's face it, SEO was the last of their concerns.
I start my service in a second language with the same tech stack, but I have severe limitations.
I can't have folders or subdomains, so I can't separate my content with en.domain.com or domain.com

If I leave all my pages in two languages ​​in the same (root) folder, but the link rel is alternatively and href well defined, can this still be okay for Google?

SEMrush

I know it's far from ideal, but as far as search engine optimization is concerned, can I hope I'm okay (I'm doing it right now and growing in just one language), or will it mess up my entire website?

Well worked out with the sitemaps, of course.

However, I can put a parameter in the URL to distinguish the languages, but I think this would be worse than what I explained above.

Any feedback much appreciated!