If you already have a Mapsly account with your HubSpot added as a data source there and you would like to link your Mapsly account it to your HubSpot organization so your users can sign into Mapsly using their HubSpot user accounts:
go to Mapsly login page at app.mapsly.com,
click the HubSpot logo,
in the pop-up that will open select your HubSpot account and enter your HubSpot credentials,
on the screen below click Link existing Mapsly account and enter your Mapsly account login and password:
This will link the two accounts via Single Sign-On.
Please note that you need to be the administrator of both your HubSpot and Mapsly organizations to complete this guide, and this guide assumes you had installed previously installed the Mapsly extension and entered HubSpot API key in Mapsly as described in the Mapsly setup guide for HubSpot.