curl --location --request POST 'https://api.inboxkit.com/v1/api/mailboxes/username' \
--header 'X-Workspace-Id;' \
--header 'Content-Type: application/json' \
--data-raw '{
"uid": "string",
"username": "new.username"
}'
{
"error": false,
"message": "Mailbox updated successfully"
}