Dot net 3.5 not available in windows feature box.

Dot net 3.5 not available in windows feature box. only 4.8 available. I installed 3.5 from standalone version as per microsoft guide . but still 3.5 not showing any version installed on my device windows 11 26H1 . i am unable to do my study for this problem . plz help me to comeout from this problem