CANNOT OPEN THE SPECIFIED FILE with tel:-hyperlink

You may check on below:

1.    Check Windows default apps
o    Go to Settings → Apps → Default apps → Choose default apps by protocol.
o    Scroll down to TEL and see which app is assigned. If it’s blank, assign WhatsApp (or another calling app).
2.    Test outside Excel
o    Open a browser and type tel:+123456789.
o    If nothing happens, Windows doesn’t know what to do with tel: 
3.    Excel Trust Center
o    File → Options → Trust Center → Trust Center Settings → External Content.
o    Make sure hyperlinks aren’t being blocked.
4.    Recreate the hyperlink
o    Right-click → Edit Hyperlink → re-enter tel:+number.