Find the issue types
https://<instance url>.atlassian.net/rest/api/2/project/WIZ
Find transition ID's
https://<instance url>.atlassian.net/rest/api/2/issue/WIZ-<id of ticket>/transitions
Find custom field values
Under here you will get a lot of custom fields, to work out what they are, use the below
https://<instance URL>.atlassian.net/rest/api/2/issue/WIZ-<id of ticket>/editmeta
You then get something like
"customfield_10004": {
"required": false,
"schema": {
"type": "number",
"custom": "com.atlassian.jira.plugin.system.customfieldtypes:float",
"customId": 10004
},
"name": "Story Points",
"key": "customfield_10004",
"operations": [
"set"
]
},

Find the issue types
Find transition ID's
Find custom field values
Under here you will get a lot of custom fields, to work out what they are, use the below
You then get something like