need help with outreach at a "local" AI law startup (i will not promote)

I am the founder of a central European AI lawyer platform. Right now all the leads come from Google SEO, people searching "lawyer AI" (in local language) When i made the SaaS it was very basic, almost like a PoC, unusable for real lawyers, however at the time i didnt care, i posted it on local reddit ("young local founder made AI law startup") and it gained a lot of traction and even got me an article at a local news site, which pulled a lot of traffic, but ever since then the traffic died down (obviously the product was bad). The obvious answer is to just make a reddit post bu the original one highlighted how I was a young founder and that it is a free project and now we became a bit more corporate. It's still doable and we offer free tiers, but I am putting it off. Emailing our previous users, already on the table and doing in waves. People are coming over. Other than that it's just the SEO, so I'm looking for some way to turn a dial and throw money at it and get some traffic of actual lawyers or practicioners that would be power users and work with documents a lot, I'm not expecting miracles just experiment with it and hopefully make some money. What would be the best way to reach them? Google ads? (I've never used GA, do I have to select keywords or something?), Facebook ads?, LinkedIn?