Step 1 is getting the app downloaded.  Chrome may present the warning of:  not commonly downloaded and may be dangerous and propose you discard.  Instead, look for the arrow icon pointing up and choose to keep.  The open the downloaded app and confirm.

Step 2

Generally, you'll be prompted to open the Security and Privacy Panel > Privacy Tab automatically - but if you click out the prompts you'll need to follow these steps:

  1. Open System Preferences > click on the Security and Privacy panel > within the Security and Privacy panel look for the tabs across the top and select the Privacy Tab > then on the column on the left find Accessibility and select it
  2. Click the lock in the corner of the window to unlock the Security and Privacy settings
  3. Next, find either "ConnecWise Control Client" -OR- screenconnect- followed by a string of letters and numbers. - and check the Allow box
  4. On macOS Catalina (10.15 or higher) you also need to allow Screen Recording as pictured below
  5. After allowing screen recording access, you should see a small window open asking Later or Quite Now - Latertends to work fine