@Mercy,
If the launcher cannot find the D3 programme, that is likely a different problem.
There is an option in the BattleNet Settings to scan for Blizzard games…
Also, until such time as you reach trust level 3 and can post links, you should learn the workaround for posting links (putting spaces in the URL is NOT a workaround).
- Post the link in your text as you would normally,
- Highlight the entire link; and
- Click on the </> button in the formatting bar at the top of the input window.
Your link would appear as : https://imgur.com/ok39sXo