Adding new columns from rows with the same unique key value

DAX-only pattern that pivots rows into numbered columns.

1-Add a per-key position in Charges (calculated column)

Sort order: by ChargeCode (change if you prefer another order).

Pos =
RANKX(
FILTER(Charges, Charges[ProUK] = EARLIER(Charges[ProUK])),
Charges[ChargeCode],
,
ASC,
DENSE
)

2-Create the wide table (calculated table)

Adjust N (here N=3) by adding more pairs.

Charges_Wide =
ADDCOLUMNS(
SUMMARIZE(Charges, Charges[ProUK]),
"ChargeCode1", CALCULATE(SELECTEDVALUE(Charges[ChargeCode]), Charges[Pos] = 1),
"LineCharge1", CALCULATE(SELECTEDVALUE(Charges[LineCharge]), Charges[Pos] = 1),
"ChargeCode2", CALCULATE(SELECTEDVALUE(Charges[ChargeCode]), Charges[Pos] = 2),
"LineCharge2", CALCULATE(SELECTEDVALUE(Charges[LineCharge]), Charges[Pos] = 2),
"ChargeCode3", CALCULATE(SELECTEDVALUE(Charges[ChargeCode]), Charges[Pos] = 3),
"LineCharge3", CALCULATE(SELECTEDVALUE(Charges[LineCharge]), Charges[Pos] = 3)
)

Result
One row per ProUK with ChargeCode1/LineCharge1, ChargeCode2/LineCharge2, etc.
If a key has fewer rows, missing pairs will be blank.