You have narrate and hand-hold these bots like they are idiot RP partners or players at your GM table. They need material to work with and they need constant reminders to stay on task. Just like the aforementioned humans, they will forget relevant details over time, meaning you need to amend and correct when they're wrong to keep up the illusion.
Some advice: Star ratings and right-arrows can help encourage/discourage answers. Do not allow yourself a passive voice in the rp- even if you are pretending to be meek and feeble, provide hard set 'narrative scene direction' via comments added within Asterisks. Related to the prior, ensure the bot has a clear understanding of your prompts by using quotation marks to designate when you are speaking. Bots are inherently reactive, so give them material aimed at producing the result you want- by way of accentuating certain details or, again, scene direction. Finally, remember above all that unlike real rp with humans, bots don't have feelings or have posessive qualities tied to their words- if they make a mistake, use the edit button to redact or amend the reply, and feel free to take narrative control of their character at critical moments via asterisk comments on 'your turn'.
Above all just bulldoze down any preconcieved notions of 'me as equal player' you may have from human RP's and take dominant, narrative control of the entire scenario.
One last tip, these bots minds degrade over time, literally rot before your eyes; keep sessions somewhat tight, and delete chat records when done; then, when you want to start a new big scene or arch, have your first couple messages set the scene- who you are, who the bot is to you, important narrative details needed for the new scene ahead.