21's normally have dual golf cart (GC2) 6V batteries in series for 12V, I believe Escape provides Interstate's premium grade which are rated for around 220AH.
fwiw, 2019 lead acid batteries are pretty much nearing their EOL. Sure, they might work for a couple more years, but they might die overnight.
When two batteries are in series, you add the voltages (6V + 6V = 12V total) and the AH remains the same, whereas if two batteries are in parallel, the voltage is the same as either one, but the AH is added, so my two 12V 206AH Lithiums provide 12V 412AH in parallel. Note AH for lead acid batteries is kind of theoretical in that you really should avoid discharging lead acid batteries below 50%, so dual golf cart batts are really only good for like 12V 110AH, which is 1320 watt*hours of power, and typipcal golf cart batteries are good for maybe 300 50% discharge/recharge cycles... Lithiums, on the other hand, can be discharged to nearly 0% 1000s and 1000s of times, so my 412AH 12V is actually 5260 watt*hours usable power. basically, I can dry camp without any sunshine for over a week... and my 360W solar panel (not original) will fully recharge that batt in about 1.5 days of full sunshine. The downside of lithiums, you need chargers with a lithium profile.. some WFCO 8955 power centers (which is what the Escape 21 came with) have a jumper for this, others, you can replace the power converter module in the 8955 with a PD4655L lithium compatible power center. The Victron Smartsolar controller can be reconfigured with the Victron Connect phone app, as can the Victron SmartShunt so it shows the right % for whatever battery combination you install.
if this has been too much tech talk, sorry. i'm a retired engineer, this stuff is all second nature to me.