For Jira Server Real time Synchronization you can create Webhooks in Jira.
Create webhook in Jira for Real-time Synchronization
Since webhooks in jira do not support authorization, it is impossible to perform a callout in SF. To do this, you need to create a community site, and give Guest User access to the Apex class
1. Create a site
Click on ‘Get Started’.
And enter the Name of the site. Click on ‘Create’.
Click on ‘Activate’.
2.Give Guest User access to the peeklogic_jc.JiraServerRestService apex class
Click on ‘Public Access Settings’.
Go to ‘Apex Class Access’ and enable Apex Class ‘peeklogic_jc.JiraServerRestService’ and ‘peeklogic_jc.JiraServerVersionRestService’
3. Generate and paste an API token in the custom settings. (maximum length 128 characters)
You can use the free site https://generate-random.org/api-token-generator?count=1&length=128&type=mixed-numbers&prefix=
the token must contain only numbers and letters. If you want a token with special characters, you need to decode it.
Paste in Jira Admin Settings, API token field.
Create Named Credentials for callout in Salesforce
and paste their API name in Jira Admin Settings.
4. Generate URLs for Jira Webhook
{site-URL}/services/apexrest/peeklogic_jc/JiraServerIssueAPI?issuekey={issue.key}&apitoken={your token saved in custom settings}
4.1 Generate URLs for Jira Webhook Fix versions:
{site-URL}/services/apexrest/peeklogic_jc/JiraServerVersionAPI?versionid={issue.key}&apitoken={your token saved in custom settings}
the red one needs to be replaced with {site-URL}
It should turn out like this url
For fix versions:
5. Create a webhook on Jira with the generated URL
Paste the URL you generated in the previous step.
Create a webhook for fix versions on Jira side: