Calculating the sum for unique ID within each transaction

Hello Splunkers,

I have two different sourcetypes that can be grouped by a unique id where one sourcetype has some numerical value and another ends with transaction "END" such as below:

sourcetype1

unique_ID, field_A

a, 10

b, 20

c, 5

a, 20

c, 30

sourcetype2

unique_ID, field_B

a, END

b, END

c, END

I would like to calculate the sum of field_A between "END" status for unique_ID.

What I have done so far is:

sourcetype=sourcetype1 OR sourcetype=sourcetype2 | transaction unique_ID startswith="END"

Any help is welcomed.

Thanks in advance.

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