In Jira Software, story points are implemented via a custom field called "Story Points". 

 You can sync JIRA Story Points field as a simple text field.

Note!

Make sure that you have Story Points field on both sides.

 

Source side

Add the code below into the Data Filter to send Story Points field data

Data Filter

replica.customFields."Story Points" = issue.customFields."Story Points"
 

Destination side

Add the code below to the Create and Change Processor to add synced Story Points field data

Create/Change Processor

issue.customFields."Story Points".value = replica.customFields."Story Points".value