Teams compatibility

Hello,

I have a question regarding teams integrating with Outlook.

I have an on prem exchange (ex 2013) and i have users with outlook 2019

When I install teams I do not get the little icon in outlook for Microsoft teams.

I check the addins and it's not there in outlook 2019

The teams account is logged on as mailto:username@domain.com and the outlook is logged in with the same email address mailto:username@domain.com

Is this some kind of limitation between on prem exchange and ms teams?

Do I need to have an office 365 license to have the end users get that ms teams addin in outlook and give them access to create teams meetings and schedule things from within their outlook?

THanks!