In Jira, story points are implemented via a custom field called "Story Points". You can sync JIRA Story Points field as a simple text field.
Important: Make sure that you have Story Points field on both sides.
Source side
Add the code below into the Outgoing sync to send Story Points field data
Data Filter
1 replica.customFields."Story Points" = issue.customFields."Story Points"
Destination side
Incoming sync
add synced Story Points field data
1 issue.customFields."Story Points".value = replica.customFields."Story Points".value