Grouby_concat Metabase MySQL

Question

I am trying to merge the same ID's together, and create a column with all the values in Client Custom Field__value. I cant seem to be able to use groupby_concat correctly.

Here is the original SQL:

SELECT `clients`.`id` AS `id`, `clients`.`name` AS `name`, `clients`.`created_at` AS `created_at`, `Client Custom Field`.`value` AS `Client Custom Field__value`
FROM `clients`
LEFT JOIN `client_custom_field` `Client Custom Field` ON `clients`.`id` = `Client Custom Field`.`client_id`
WHERE `clients`.`type` = 'client'
LIMIT 1048575

Here is the one I edited to group:

SELECT `clients`.`id` AS `id`, `clients`.`name` AS `name`, `clients`.`created_at` AS `created_at`, groupby_concat(`Client Custom Field`.`value`) AS `Client Custom Field__value`
FROM `clients`
LEFT JOIN `client_custom_field` `Client Custom Field` ON `clients`.`id` = `Client Custom Field`.`client_id`
WHERE `clients`.`type` = 'client'
GROUP BY `id`
LIMIT 1048575

I get this message: execute command denied to user 'base_prd_metabase_read'@'10.192.2.6' for routine 'base_prd_system_baseservice.groupby_concat'

I added a picture for visual representation. First time using MySQL, so a easy explanation and reasoning is highly appreciated!

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