I hope you can offer the permanent solution. If not, I the service becomes worthless, unfortunately.

Hi Praveen, looks like YouTube blocks repeated API requests primarily to prevent abuse. I think I know how you can deal with this issue. I stumbled on it in the past during reading top 20 google search results). Google was blocking my server IP after few requests. I found solution - proxy rotation. I used this - https://proxiesapi.com/
But this was for google searches.... Anyway, you can try.