Then you may use the older version...
I actually attempted to install an older version on a friend's pc, today. None of the older versions had a checkbox for Remote Assistance. I even used Avastclear to remove the installed Avast version.
Count me among those who are disappointed with this decision. I have an extended family I provide tech support for (no charge). I have Avast installed on all of their computers---some use the free version, others have opted for a paid subscription.
Several changes over the years have prompted me to consider another AV. SafePrice addon (before it was optional), SafeBrowser install (without even asking--and with some rather disturbing security issues), Cleanup added to the free version (simply to pop up an enticement to upgrade---it didn't actually work in the free version), etc.
I don't begrudge Avast a way to make money, and/or promote upgrading to users of their free version. But some of the methods ("Your Firewall is Disabled!") seem a bit unscrupulous. for a security company trying to maintain a good reputation.
I have an idea. Why not make the Remote Assistance available in the paid version? Clearly there are many who use it, and it might give some free users an actual reason to upgrade. I'd force all my relatives to pay $30, or so, for this feature. Yes, I know there are other options. But if you ever had to do computer support for the elderly, and other completely unsavvy computer users, you might appreciate what a bonus this simply remote application has been.