How to put labels in google map from db array on worpress site?

Question

Google Maps

Given:
Database (DB1) where map tags (coordinates of companies) are stored, which is constantly updated.
There is a website on Wordpress with its own database (DB2).
It is necessary to display a map with labels from database 1 on a site running wordpress.
As I understand it, direct access to DB 1 through php cannot be done (not safe).
The idea is this:
1 place an executable file with functions for connecting to the database 1 and loading it into an array of coordinates in the template folder.
2 on the site through the php widget, use the function of initializing google maps and outputting an array of labels.
Or is there a plugin that does this already? (looked at 6 plugins, empty)
Thanks for the help!