How to use "QA_InvalidScans" as covariate in second-level analysis

Dear CONN experts,

I am using CONN version 20.b and have read in the manual that it is possible to use "QA_InvalidScans" as a covariate in the second-level analysis. Unfortunately, it is not clear to me how to do this. How can I add this covariate to the second-level analysis ? It does not appear under my manually entered covariates (age and sex).

I would be grateful for any help on how to do this.

Thanks in advance.

Katja