The main HTML code for the ProMaps pages is located in two fields on the "MapSettings" table; MapDataTemplate and RouteDataTemplate
MapDataTemplate contains the code for the Map and Constrain views, and the RouteDataTemplate field for the Route view.
Always save a copy of your file before making changes to the map HTML
If you'd like to do some more advanced editing of the code in your ProMaps solution, you can do so by adding these fields on to a layout based on the "MapSettings" table. It's probably best to just create a new layout for this.
Editing HTML can be a bit difficult directly in FileMaker fields, so we suggest copying the contents of the field, then pasting them into a document in a text editor made for HTML code (such as Atom). Once you've made the changes, you can copy them into your clipboard, delete all the contents from the field in your ProMaps file, then paste the clipboard contents back into the field.
For the changes to take effect, you'll need to either close and re-open your solution or click the "Apply Settings to Map" button on the "ProMaps Setup" layout.
Inspecting the HTML in a browser
Since ProMaps exports the map page to a temporary directory to be viewed in the WebViewer, you can also view the exported pages in a browser to inspect the code and CSS styling.
To do this, just go to the map view you want to load in the browser, copy the link from either the "$$sc_MapURL" or "$$sc_MapRouteURL" variables in the data viewer, then navigate to that page in the browser.
You can then use the browser's developer tools to inspect the code.