Hi @Or Bauberg ,
your user needs the permission to read the Cost Management information in your Azure Subscription.
Please take a look here: Assign access to Cost Management data
In short: Your user should be member in the Cost Management Reader
RBAC role in your Azure Subscription.
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten