Hello Samuel,
Thank you for your message.
I do not know where you must send your placement test result, but I can recommend that you contact your Erasmus+ coordinator. This person is usually the person who sent you the invite link to the OLS platform or the person who is supervising you during your Erasmus+ mobility program.
If that option doesn't work, you may try contacting the National Agency for your country of origin and ask to whom your test result should be sent.
The National Agency information can be found here:
https://erasmus-plus.ec.europa.eu/contacts/national-agencies
Do you know anyone else in your mobility program that you can ask?
Perhaps someone in our English community will join our conversation to add what they know.
In the meantime, I hope this information helps. Let the community know if you were able to find a solution. Maybe your situation may be helpful to someone else in the future!
Wishing you a lovely day,
Iya