Try this: {G2Q00001_question.qid}

Thanks for your answer, but how ro retrieve current question id ? I need to add this variable in this field and also in a Java script associated with a question ?

Set the default answer for question "G2Q00001", subquestion "question" to be {G2Q00001_question.qid} and check if that works. (Instead of {QID} in your screenshot "QID error .png")

Thanks again, and I apologize for asking again: my precedent answer wasn't clear enough : you're right, the solution you've proposed works perfectly.
But remains two questions for me :
1- why can't I get {QID} or {GID} of the curent question, as default answers (see attached file)
2- How to get variables in the javascript tab of a question : I'm creating a question type, that will be reused many times in one survey and other surveys so that each time this question type will be assigned a new id. This question own a javascript that forms a name that must get and use : survey, question, suser ids : here is my actual script that works :
const defaultClipName = formattedDateTime + '_{idssurvey.NAOK}{idsgid.NAOK}{idsquestion.NAOK}{idsfamily.NAOK}{idsperson.NAOK}{ids2parentorchild}{ids2_gender.NAOK}';

Where ids and ids2 are previous questions codes, and survey, gid, etc are multiple answers codes.

But I'd like to adapt this script in order to access directly to variable, and would looks like :
const defaultClipName = formattedDateTime + '{SID}{GID}{QID}{{TOKEN:ATTRIBUTE2}}{{TOKEN:ATTRIBUTE1}}{TOKEN:ATTRIBUTE4}{TOKEN:ATTRIBUTE3}{TOKEN:ATTRIBUTE_5}'

What type of question is record?

If it has subquestions, you need to do something like record_SQ001.qid and record_SQ001.gid instead (it doesn't matter which subquestion code you use)

Hi mfavetti, thanks for your reply.

As per the comments, I think all is good and will be closing the ticket.
Please add any comments in case it should be reopened.
Thanks