Cannot SUM Goals Dimension because of Automated Data Type

Hi everyone,

I have a lot of difficulties linking my Matomo Tools to Looker studio. I takes me several hours to pass credentials issues everytime i tried to open a looker.

Morevover, I have Conversion Goals that I want to sum directly on Looker and I can’t. In fact, the goals dimension is auto set as text and cannot be seen as number.

Do you have any idea how i can do that ?
thanks