Thanks for getting back with the Community, christophe-picha.
 

If you've already performed each of the troubleshooting steps in ShaniamarieC's post, and confirmed your accountant is checking their spam/junk folders for the invitation, but they're still not receiving it, I'd recommend getting in touch with our Customer Care team.
 

They'll be able to pull up your account in a secure environment, conduct further research with you, and create an investigation ticket if necessary.
 

They can be reached while you're signed in.
 

Here's how:

1. Use the Help (?) icon.
   
   
    
2. Click Contact Us.
   
   
    
3. Enter a description of your situation in the What can we help you with? field, then hit Let's talk.
   
   
    
4. Select Start messaging or Get a call.
   
   

Be sure to review their support hours so you'll know when agents are available.

If there's any questions, I'm just a post away. Have a lovely Wednesday!