K6 is my go-to for performance testing. What drew me in is that you can convert Postman collections to k6 scripts (https://github.com/loadimpact/postman-to-k6) if you already have Postman collections. If you don't have any Postman collections, you can just start with k6 and you can have a simple script up and running in under a minute. I've used k6 at work and for personal projects testing Scala, Go, and Python (I guess the language you're testing doesn't matter b/c you're just hitting http endpoints). If you're doing testing that requires getting an OAuth token, there's a flow for that. I've had nothing but good experiences and would heartily recommend k6 if you're looking to performance test!