The daily login rewards system works in such way that, if you have not signed in for one day, then the system will revert your reward to one day back, if you did not sign in for two days, it will revert to the latest big reward, and if you missed three days - the reward counter will be reset.
A new option was introduced to War Thunder, allowing you to keep the current daily login progress by logging into War Thunder Mobile.
For this you would need to log in with your Gaijin account into mobile version of the game, or link your War Thunder Mobile account to your Gaijin account, if you already started playing War Thunder Mobile with another login option.
You can link accounts with the help of this article: Linking Google/Apple/Facebook game account to Gaijin account.
Please note:
1.Logging into War Thunder Mobile does not progress the daily login counter in War Thunder.
2. Logging into War Thunder Mobile does not let to take login rewards in War Thunder.
3. The login progress in War Thunder and War Thunder Mobile become connected, and the penalty will be received in both projects, if a certain amount of days was missed.