hold your power button and a few options will pop up continously press power of icon until it turns to recovery mode with a green icon then click it after phone restarts go to settings and clear cache mark it as solution if it helped
this procedure is slightly changed in Android 11. you can't enter the recovery mode like the previous Android software..
First switch off your phone. Then plug in the charger cable into your phone's charging point and connect your phone to any computer or laptop or charger adapter. Then press volume up +power key button and hold for few seconds and you will enter the recovery mode.
If you don't know this feature. You can watch any YouTube video regarding this. everything will be clear. But before you proceed I suggest you to watch a YouTube video. Otherwise one mistake might cost you more...
2. Settings>>Location>improve accuracy >disable A. Wifi scanning B. Bluetooth scanning .
3. Device care>battery >power mode>select "optimised" and "adaptive power saving".
And then click on "app power management > And enable these 2 options. A. Adaptive battery B. Put Unused Apps to Sleep.
4. Long press on each app specially 3rd party app(LIKE FACEBOOK, YOUTUBE) and rarely used apps and also ON "GOOGLE APP" as well, then click on>app info> go to these 3 options below on by one
A. Mobile data> allow background data usage>off
B. Battery >allow background activity >off
C. Notification >disable unnecessary notifications like promotional and unnecessary reminder notifications.
5. Go to settings> privacy > permission manager > location> and check which app have accessing your location all the time and if you not using that apps much, then deny access or set as " allowed only while in use" As unnecessary location access by 3rd party app causing battery drain.
6. Go to settings > Google > on device sharing> check which 3rd party apps present there for e.g. if you use paytm , paytm will shared data to show recommendation and suggestion which also cause battery drain
7. Go to settings > account and backup> account > check which app syncing automatically there, and if any app which not necessary to auto sync then click on it and "disable sync"
8. Go to settings >apps>search "weather" >click on settings icon right side > change "auto refresh" settings as per your requirements and disable some unnecessary reminder. ( due to auto refresh it continuously consuming battery)
9. If you use Facebook frequently then disable "auto play video" And if you are mostly uses mobile, on wifi connection then also disable "auto play videos" in YouTube.
10. Settings>Google >click on 3dot at right top corner>usage and diagnostics >off this option.