When summarising data in a SELECT statement you would never use UPDATE. You are doing one or the other not both (although you can update a table based on the results of a SELECT, but the image does not imply that that is what you are trying to do).
From the image provided it looks like a straight forward "GROUP BY"
SELECT
SUM([Betaling (brutto)]) as [Betaling (brutto)]
,SUM([Betaling (netto)]) as [Betaling (netto)]
,SUM([Bestillingsgebyr (netto)]) as [Bestillingsgebyr (netto)]
,SUM([Betalingsgebyr (netto)]) as [Betalingsgebyr (netto)]
,SUM([Oppdragsgebyr (netto)]) as [Oppdragsgebyr (netto)]
FROM
tblTripsPerMonth
GROUP BY [KjøretøyID], [År], [Måned]
That will give you one row per [KjøretøyID], per [År] and per [Måned]. With the data you provided it will give the results on the right.
A couple of other points.
- Stick to English or Anglicized names for columns and avoid spaces and things like (brutto). Having to put Square Brackets around every column quickly becomes very tiring.
- When giving sample data here in QA don't use images. Just provide the code that will populate the sample data (with the value!) or at least provide that table in text format here so we can copy it easily.
- Same goes for the expected results - I'm at work in my lunch break and do not like following links outside this site just to help someone in my spare time
- Try to stick to just the relevant detail - it doesn't matter that this is a Stored Procedure and it doesn't matter that you are using a user-defined table type - you are essentially just trying to summarise some data. Small steps.
Edit after OP comments:
It seems that you only really want to group by [KjøretøyID] so try this instead
SELECT [KjøretøyID]
SUM([Betaling (brutto)]) as [Betaling (brutto)]
,SUM([Betaling (netto)]) as [Betaling (netto)]
,SUM([Bestillingsgebyr (netto)]) as [Bestillingsgebyr (netto)]
,SUM([Betalingsgebyr (netto)]) as [Betalingsgebyr (netto)]
,SUM([Oppdragsgebyr (netto)]) as [Oppdragsgebyr (netto)]
FROM
tblTripsPerMonth
GROUP BY [KjøretøyID]
That is going to give you the results
AG4203000002 5699 5376.40 147.16 80.62
AG4203000003 1190 1122.64 22.64 19.84
Notice that [År] and [Måned]. If you want to include those extra columns in the summary, you cannot just add them to the Group By clause, you also need to add them to the Select ... and from what you are saying in the comments that is returning too many rows.
Perhaps include some sample data where [År] != 2021 and/or [Måned] != 7 ... work out your expected results from that revised sample and share that.