Invalid region parameter when retrieving S3 storage containers

Hi,
I've been trying to do a bunch of stuff with OVH's API to know if it suits my needs and whenever I try to list all my S3 storage containers I get this one error saying 'invalid region parameter'.

!error|690x293

Am I doing anything wrong? Im using the region name given by the /cloud/project/{serviceName}/region endpoint so I dont know if I should be using any other name

!regions|690x457

Thanks for your help