With Open Street map you can show information related to the locations you add on the map. This information is then visible in a popup called the Info Window popup.
To display the Info Window popup go to any Location > Choose the action to Display the Info Window on Hover or Mouse click.
After selecting the action, you can now add the Title & Description in the space provided.
Follow similar steps to add the Info Window on other locations. To style the Info Window and its content go to the main Style tab.
For styling just the popup, go to Style tab > Info Window, where you can set the background color, width of the popup and others.
For styling the Title & Description each, go to Style tab > Address Title/ Address Description where you can add the text color and change it typography settings.