Hi @mingheng_moka,
Thank you for the URL. You are only receiving 100 deals per call because you are using count=250 instead of limit=250.
The count parameter is used for the Get recently modified deals endpoint while the limit parameter is used for the Get all deals endpoint.
Use this request URL instead:
https://api.hubapi.com/deals/v1/deal/paged?hapikey=XXXXXXXXXXXX&properties=dealstage&properties=invoice_number&properties=createdate&properties=closed_won_reason&properties=closed_lost_reason&properties=pipeline&properties=dealtype&properties=amount&properties=hubspot_owner_id&properties=activation_email&properties=hs_lastmodifieddate&limit=250&includeAssociations=true