If you are using a free, trial account, you can upgrade it to a Pro account to enjoy the Talllly benefits. Click on your account name drop-down list and select Settings option.
Select Billing option, as below.
Click on Add Credit Card button and add your card details. Talllly confirms that the transaction is complete as you get an email at your registered email address.
Now your account is upgraded and you can continue using it beyond the trial period.