code: @SuppressWarnings({"unused", "WeakerAccess"})
      public static void changeCredentials(String accountID, String token, String region) {
          if(defaultConfig != null){
              Logger.i("CleverTap SDK already initialized with accountID:"+defaultConfig.getAccountId()
                      +" and token:"+defaultConfig.getAccountToken()+". Cannot change credentials to "
                      + accountID + " and " + token);
              return;
          }
  
          ManifestInfo.changeCredentials(accountID,token,region);
      }
docs: This method is used to change the credentials of CleverTap account Id, token and region programmatically
  @param accountID CleverTap Account Id
  @param token CleverTap Account Token
  @param region Clever Tap Account Region