Yes, if self-represented buyers or buyer's agents make offers using the online feature, their commission can be included (and negotiated) online.
Here is how it works:
If the seller is offering a commission to the buyer's agent, that amount will pre-populate the offer feature associated with the listing.
The buyer or the buyer's agent making the offer can amend or approve that amount (visible in the "terms" section) as they draft the offer and submit it to the seller.
When the seller receives the email notifying them of the offer and opens up the offer details, they can agree to the buyer's agent commission term or counter it as they see fit.