we hv developed an Uber type of app for healthcare.. we want to approach companies.. how can be approach

There are many details that this question is missing however, from what I have gathered and based on the growth of Hela Job (my startup), we have mainly used automation tools to our advantage and generated leads to pitch our service or schedule a demo where we sale our services. I can definitely help, let's create waves together. Request a call now: https://clarity.fm/antypas.

I would need a lot more details to properly help you with this, but in general the first stage is to understand who your target market is - this isn't always who will use the software, but who will be paying for it. Depending on who this is, you would decide how to target them. For example, if it is the COO of the hospital, then you would try find a mutual connection, get an intro, and do a demo (cold emails probably won't work).
If, on the other hand, the person paying is the patient, then you would go about it entirely differently.
The method also depends on the country, type of service, cost of service etc.
Bottom line: I'm happy to help, but you need to provide a lot more details.
Good luck
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Sounds like you need a framework for segmenting the healthcare market, eg do you wan to target the delivery system, payers, government entities, vendors, direct to consumer, risk bearing entities, etc. Is this a non-emergency transportation service? Does this address social determinants of health (SDOH)? Depending on these answers and the product there are various customers. Happy to discuss more if you like.