Issue in Update query - sql-server

Question

I have two tables called PassengerPaymentDetails and RoomInfo. Following is the query that I used to extract some values from existing PassengerPaymentDetails table.
SELECT
COUNT(*) AS Count, RequestReference, RoomTypeID, RoomCategory
FROM
[UL_SLHEV].[dbo].[PassengerPaymentDetails]
WHERE
Status != 0
GROUP BY
RoomTypeID, RoomCategory, RequestReference
As you can see I have RoomTypeID, RoomCategory and Count in the above mentioned table.
Following screenshot has the RoomInfo table:
I want to update the RoomInfo table data from the extracted Passengerpaymentdetails table. I can map these two tables with the RequestReference.
Need to update the count value in RoomInfo table according to the Passengerpaymentdetails table count value. Can anybody please help?
UPDATE:
Following is the code that I have tried so far. It is correctly return join table. I don't know how to set the value to the RoomInfo table with the getting table. And also here I am using left join for some purpose. I want to insert the value as well if the left table contains new row with the new roomtypeId. otherwise if the right table contains the same roomtypeID update the roomInfo with the updated value from passangerpaymentdetails table.
SELECT
t1.RequestReference as RoomInfoReq,
t1.Count as RoomInfoCount,
t1.RoomTypeID as RoomInfoID,
t1.RoomCategory as RoomInfoRoomCat,
l.RequestReference as PassangerReq,
l.Count as PassangerCount,
l.RoomTypeID as PassangerRoomTypeID,
l.RoomCategory as PassangerRoomCategory
FROM (
select
count(*) as Count,
RequestReference,
RoomTypeID,
RoomCategory
FROM
[UL_SLHEV].[dbo].[PassengerPaymentDetails]
where
Status!=0 group by RoomTypeID, RoomCategory, RequestReference)
as t1
Left JOIN RoomInfo as l on
t1.RequestReference = l.RequestReference and
t1.RoomTypeID = l.RoomTypeID and
t1.RoomCategory = l.RoomCategory and
l.Status!=0)

Answer 1

Something like that. It would be good if you provide DDL and DML instructions to test that, however you can see the logic how to do that:
UPDATE ri
SET [COUNT] = rd.[COUNT]
FROM RoomInfo ri
JOIN (SELECT
COUNT(*) AS [Count], RequestReference, RoomTypeID, RoomCategory
FROM
[UL_SLHEV].[dbo].[PassengerPaymentDetails]
WHERE
Status != 0
GROUP BY
RoomTypeID, RoomCategory, RequestReference) rd ON rd.RoomTypeID = ri.RoomTypeID
AND rd.RoomCategory = ri.RoomCategory
AND rd.RequestReference = ri.RequestReference