Follow the instructions below to enable Pipeline Builder's advanced geotemporal series features and add a geotemporal series sync output as a reference to a geotemporal series object type:
Navigate to your pipeline in Pipeline Builder.
Select Settings > Pipeline feature flags... from the top ribbon.
Ensure that Enable advanced geotemporal series features is set to Enabled before you close out of the Pipeline feature flags window.
Select the link icon to configure your GTSR property type as a Geotemporal series > From this pipeline > Geotemporal Series Sync Output. Alternatively you may select any geotemporal series sync in Foundry, including those created by other Pipeline Builder pipelines, with Geotemporal series > From Foundry...
Save your changes by selecting the green arrow icon in the top ribbon.