Each fiscal year has its own web page, so you must sign in to each fiscal year that you need to prepare separately – here is the link to get you started - https://turbotax.community.intuit.ca/replies/2647677
Make sure you are registered with MyCRA to access all your Tslips for each year in question. Here is where you will find this information - https://bit.ly/2BPw41p
The software is easy to follow, simply answer each question based on the taxation year you are preparing.
All credits will be applied accordingly, see below for more details
The new 2018 refundable credit has no income cap but does have varying amounts by location. If you have a spouse, only one spouse makes the claim for the family (spouse and minor children). Software does it all for you – just enter a few details on your address and family.
Please note, this credit is automatically applied to your tax return, based on the initial entries at the beginning of your tax return starting with the province entry, even before you enter your income and expenses. This is a Federal Tax Credit that is reflective of the province you live in.
You will be able to claim the Climate Action Incentive under the Provincial tab.
Once that section has been completed, then the amount will calculate on line 449 of your Detailed Tax Summary Page, which is located in the Review Section of your Return after you open Bottom Line Tax summary.
Climate Action Incentive eligibility as per the CRA here https://bit.ly/2UEy2v1