Er...

You don't require investors, you require customers.

I know many people running this type of business.

Startup cost is $0.

Well, whatever your site hosting costs every month.

Best starting point is just to research other Medical + Dental Tourism companies. Clone what they do.

Pay your time generating clients, not looking for investors... which you don't require... which will ask for a large chunk of your business... and likely won't talk with you, if you're just starting.

Intone this mantra all day long...

Customer not Investors...

Customer not Investors...

Customer not Investors...

I know someone who owns a fairly large medical tourism company. If you have a steady flow of paying clients, he might be interested in investing or some sort of partnership.
If you meant that you're interested in increasing the amount of clients that you have, then I'm happy to give you some pointers, but I would need a lot more information. I'm happy to give you a free 15 min call to get the info, and then we can schedule a second call during which I will give you my advice.
I've successfully helped over 300 entrepreneurs, and I'd be happy to try and assist.
Good luck

Hello, I'm a physician and work as chief medical officer for a health plan in the US. I'd be interested in investing myself, but also in helping you with the idea. Happy to connect to discuss.

To find investors for my Medical Tourism start-up company the following link will be pretty helpful to you, do have a look at it: https://www.smergers.com/medical-tourism-investors/s1593i/
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath