Hi Natalia,
You might be able to use "Model attachments" function in Trimble Connect by following this steps;
1. Upload IFC file and PDF document to Trimble Connect project.
2. Select IFC model and click "View" button to open model in 3D viewer page.
3. Select model element and click paper clip button to add attachments.
4. You can browse PDF document that has been uploaded to Trimble Connect project, choose upload file from computer, or add link to object from the available url.
5. Click 'OK'
6. In model viewer page, select model element and click view object attachments from the paper clip icon tab in the right panel. Otherwise, select Model attachments tab and select file from the list.
7. Select attachment and choose the latest file revisions.
Hope you find this useful and let me know if there is anything else I can help you with.
Thanks,
Fern