Hey Harish,
There has been other questions like yours…
It was answered with a little walkthrough in this one:
It was also mentioned here: Ngrok.io - possible to link account? - Support - Local Community
And as a feature request: Ngrok.io link to registered accounts - Feature requests - Local Community
A quick search for “ngrok” returned these results in this forum, I would gracefully advise to search a bit before posting haha but don’t worry.
Hope it helps!