search all issues which label contain "defect"

How to search all issues which label contain "defect“, like label “defect:fvt”, “defect:svt” etc

There isn’t support for searching for a substring of a label name. If you want to create a labeling system where you can search for all defects, then you would need to have a label named defect and separate labels for fvt, svt, etc. You could also have a defect label and defect:fvt, defect:svt, etc labels.

I hope that helps!