Dear Peter2019!
Because I do n’t know your product model, take MA5800 as an example, you can use the FTTH End-to-End QoS Policy. This solution is also applicable to the MA5600T series products.
The FTTH end-to-end (E2E) QoS solution uses the differentiated service (DiffServ) model. In this solution, QoS parameters are carried in each packet header to ensure QoS guarantees.
Upstream E2E QoS(shown in the following Figure)

1. QoS policy on the ONT.
An ONT classifies traffic based on user ports or user-side VLAN IDs to distinguish services.
Re-marks the 802.1p priority for service packets.
Based on packet priorities, the ONT arranges packets into different priority queues by using PQ scheduling. This ensures that services with higher QoS requirements are forwarded preferentially.
Limits the upstream traffic on user-side ports. (optional).
2. QoS policy on the OLT.
Classifies traffic based on VLAN IDs and the 802.1p priority
Trusts the user-side priority or re-marks the 802.1p priority for service packets.
Implement priority scheduling and congestion management based on the 802.1p priority.
Implements DBA to limit the ONUs upstream bandwidth.
(Optional) limits upstream traffic bandwidth based on service flows.
For more details, please click FTTH End-to-End QoS Policy
Thank you!