Letter of Employment for Multiple Experience

[nvnka]

Dear Experts, please clarify this.
Got an Invitation under the CEC category.

Here is my story: Deputed to Canada first time in 2019 mid and worked till mid of 2020, by this time I had already completed one year of Canada experience. So, I am eligible for CEC. I am deputed to Canada again in 2021 last quarter and working to date. This entire experience is with the same organization.
Under CEC, claiming points for 2 years of Canada experience both 2019-2020 and 2021-Till.

For Letter of Employment, I have attached my current deputation documents(From 2021), T4, CRA notice, and paystubs.

Now my question is:
what exactly do I need to prove for Letter of Employment?
'Is it something to prove I belong to the CEC category(I Hope 2021-till date documents are fine)?'
Or
'Entire my Canada experience documents, starting from 2019 deputations, T4s, CRA notices, etc...?'

For 2019-2020 employment documents, I am attaching them under the respective employment history category.