You can find a cheap kit (less than $10) on amazon or at Walmart.
I frequently travel where there is no one but me to fix a battery or tire issue so I keep a toolbox with essentials in it. I keep it in my Jeep most of the time but can easily move it to SXS when needed.
Others have different experiences, my experiences dictated what is in my box.
Hulkman alpha 85 battery starter (works on my diesel tractor, charges phone etc.
Tire inflator- plugs into aux. outlet
Tire repair kit (T handle, rubber glue, and plugs)
1/2 inch impact driver with all the sockets needed to fit my vehicles, trailers, and SXS
Scissors jack
1-quart oil
1-gallon anti-freeze
gloves
paper towels
zip ties
duct tape
I've seen group discussions on what to pack and it soon becomes apparent that you need a U-haul to pull behind your SXS. So you may want to consider what you might want to carry.
All of this fits into a Ridgid stackable toolbox (bottom with wheels). It still takes less room than a spare in the cargo area. Others have installed spare tire mounts and that is a great option. I needed other things that I could use for any vehicle so I didn't see the need to spend more to carry a spare.