Any free npm library to block time for multiple individuals? across the world?

So, I'm building a community / mentoring website that would provide 1 on 1 mentoring to people ... and this is an international project where multiple individuals will book multiple mentoring sessions from multiple countries .

I do know about services like *calendly *... but they only talk about providing scheduling for a single account ( but here I need multiple account scheduling - for each mentor ) .

Is there a library that would integrate with react, and do this for free ?!