You need to have the contact saved in your phone's calendar to invite it, but if you don't already have it, you can add it directly within Biptt. See how:
Click the bottom right button with the "+" icon and a list like this will appear:
Select "Add contact" from the list and enter your new contact on the screen below. Don't forget the DDD!
Now just share with your contact that you are on Biptt waiting for him. From the same list as the first image, choose the best way to invite your contacts.
Choosing to invite via WhatsApp, for example, you will send a message like this:
They just need to install Biptt through the link for you to start making calls!
To add a contact in the company account, it is different. You will invite the user into your company on Biptt and for that you will need to create a login name and password. It is not necessary to have the person's phone number.
Choose the user's permissions, defining whether the person will be a member or supervisor. Then, you will have to pass the login and password data so that your teammate can participate in your company within Biptt.
To make it easier, share via whatsapp or another preferred network:
As soon as your user enters the login and password data you defined, you can make calls. If you are a master or supervisor (see article on profile types), you can edit, add or remove contacts at any time.