Ok so i managed to get the wanted output with the following source code
*Start creating the input table for the procedure CE_CONVERSION
PRICES = select id as id, in_amount as in_amount, source_unit as source_unit, target_unit as target_unit, ref_date as ref_date from :it_conv_prices;
*Here we call the CE_CONVERSION method and specifying that the result should be stored in the variable lt_uom_std_conv
lt_uom_std_conv = CE_CONVERSION(:PRICES, [family = 'currency',
method = 'ERP',
client = '900',
conversion_type = 'M',
steps = 'shift,convert,shift_back',
target_unit_column = target_unit,
source_unit_column = source_unit,
reference_date_column = ref_date],
[ in_amount AS out_amount ] );
*The select statement for the output table is an inner join using id.
et_amount =
select lt.id as id,
dm.in_amount as in_amount,
lt.out_amount as out_amount,
dm.source_unit as source_unit,
dm.target_unit as target_unit,
dm.ref_Date as ref_date
from :lt_uom_std_conv as lt
inner join :it_conv_prices as dm on dm.id=lt.id;