sfdc-jwt

v1.0.2 added support for single array object as input argument for getAccess function: [{privateKey, publicCertificate},{sfdc_consumer_key, sfdc_user, sfdc_auth_url, sfdc_oauth_url}, testBool] simple as possible

For generating certificates, unless you have a requirement to use CA issued certs, please use this openssl command: openssl req -x509 -newkey rsa:4096 -nodes -keyout openssl.key -out openssl.crt -subj /CN=SFDS -days 1000

There are a lot of bad articles and videos all over the place. The only one that I found that made sense is this one: https:medium.com/@tou_sfdx/salesforce-oauth-jwt-bearer-flow-cc70bfc626c2

Need keys and certs?

openssl req -x509 -newkey rsa:4096 -nodes -keyout openssl.key -out openssl.crt -subj /CN=SFDS -days 1000

privateKey      
publicCertificate  

sfdc_consumer_key | connected app api key (NOT SECRET)
sfdc_user_login_id | your login id (NOT THE ID OF THE APP)
sfdc_auth_url | https:login.salesforce.com
sfdc_oauth_url | https:login.salesforce.com/services/oauth2/token

testBool  | true if you want to test signing. false or null or undefined for actually using the functions