You have a starter solenoid (its on the starter) and it can be jumped.
You may not have a starter relay. You can buy or make one like this https://lowrangeoffroad.com/suzuki-samurai-clicky-starter-relay-upgrade-kit.html. There are many write ups out there on how to do it.
I put a 20R, toy trans, etc. into a samurai and with out a relay, it only sometimes could manage to turn the engine over. It just always acted like the battery was dead. I added a relay and now it turns over and fires strong. My 84 22R doesn't have a starter relay and it turns over a little slower than most. Been thinking It could probably benefit from adding a relay.

I would do what Cheesemaker suggested. Make sure all wires/connections are good and jump the starter. If the starter wont turn then it's dead. If it does, check the start wire at the starter and go from there.