How open files, by default, with a specific browser

I bought a piece of software (Standard Legal) that has many folders and files within the folders). When I open a file, it opens with Adobe Acrobat (which is fine). However, I want Adobe Acrobat to open with Chrome (Windows 10) or, at least the files to open with Adobe Acrobat under Chrome. Is this possible? If so, how do I do this? The reason I want to do this is because I use Lastpass to secure my usernames and passwords. When I open this software, it asks for me to sign in. Lastpass only works with Chrome. So, when I open this software, I want Lastpass invoked so that the username and password are filled in automatically. Thank You.

What is the file extension? It should be as simple as associate the extension to open with chrome

FYI: They state:

Standard Legal's PDF Format - Ask Standard Legal

   Note

REQUIREMENT #1: to open and use any Standard Legal PDF, you must have either the FREE Adobe Reader or the commercially available Adobe Acrobat installed on your device. We strongly recommend using the most up-to-date version of the Reader or Acrobat software, as older versions may not be fully featured.

REQUIREMENT #2: users must open a Standard Legal PDF inside the Reader program only, and NOT INSIDE A WEB BROWSER window.

   Note

Use requirements summary: DO NOT USE ANY OTHER TYPE OF PDF PROGRAM BESIDES READER OR ACROBAT. DO NOT OPEN AND WORK ON ANY PDF FILE FROM WITHIN A WEB BROWSER. Failure to follow these two critical instructions will cause an error upon saving or printing the document.

You've probably got PDF file association set to open in a browser like Edge or Chrome so change it to Adobe Acrobat.

How to set Acrobat Reader or Acrobat your default PDF program on Windows 10

Just a thought:
add adobe acrobat to chrome at DuckDuckGo