Unable to create a Defect in Jira

[Joy Nandi]

I am unbale to create a defect /Bug in JIRA and using python as below:-

from atlassian import Jira
jira = Jira(     url="https://xxxxxxxxxxxxxx.xxxxxxx.xxx/",     username='xxxxxxxxxxx',     password='xxxxxxxxx')
jira.issue_create(fields={
    'project': {'key': 'xxxxxx'},
    'issuetype': {
        "name": "Bug"
    },
     'summary': 'test rest',
     'description': 'rest rest',
     'priority':'Class 2',  
})

however same works when I replace issuetype as Task and omit priority as that is not a mandatory field.

More over I have only user privilege to JIRA and find the below:-

The screen appears for creating Issue has 2 fields Project( a drop down where I have the default project which I have access to) and Issue Type also a drop down with Incident(Defect) as the option it also has the option of UAT Bug both UAT Bug and Incident(Defect) have icon of white circle within red square.

In the create Issue page also I have a mandatory field with label as SLA Priority which is radio button with 3 options.

I am not sure how to proceed in this case.

I tried to use https://Your-JIRA-URL/rest/api/2/field however I do not find the SLA Priority as a field over there (is it a custom field ? if yes how I get the ID?)