To proceed to offer pricing you should have both a single offerID and OfferItemID of each passengers
<OffersGroup>
<AirlineOffers>
<Offer OfferID="OFFER001" Owner="ET">
<TimeLimits>
<OfferExpiration Timestamp="2023-04-17T13:18:40.8777761Z" />
</TimeLimits>
<TotalPrice>
<SimpleCurrencyPrice Code="USD">890.80</SimpleCurrencyPrice>
</TotalPrice>
<OfferItem OfferItemID="OFFERITEM-6478847636">
<TotalPriceDetail>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">463.40</SimpleCurrencyPrice>
</TotalAmount>
</TotalPriceDetail>
<Service ServiceID="SV_FLT001_PX001">
<PassengerRefs>PX001</PassengerRefs>
<ServiceRef>SD_ES</ServiceRef>
<FlightRefs>FLT001</FlightRefs>
</Service>
<FareDetail>
<PassengerRefs>PX001</PassengerRefs>
<Price>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">463.40</SimpleCurrencyPrice>
</TotalAmount>
<BaseAmount xsi:type="SimpleCurrencyPriceType" Code="USD">336.00</BaseAmount>
<Taxes>
<Total Code="USD">127.40</Total>
</Taxes>
</Price>
</FareDetail>
</OfferItem>
<OfferItem OfferItemID="OFFERITEM-2030111990">
<TotalPriceDetail>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">379.40</SimpleCurrencyPrice>
</TotalAmount>
</TotalPriceDetail>
<Service ServiceID="SV_FLT001_PX002">
<PassengerRefs>PX002</PassengerRefs>
<ServiceRef>SD_ES</ServiceRef>
<FlightRefs>FLT001</FlightRefs>
</Service>
<FareDetail>
<PassengerRefs></PassengerRefs>
<Price>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">379.40</SimpleCurrencyPrice>
</TotalAmount>
<BaseAmount xsi:type="SimpleCurrencyPriceType" Code="USD">252.00</BaseAmount>
<Taxes>
<Total Code="USD">127.40</Total>
</Taxes>
</Price>
</FareDetail>
</OfferItem>
<OfferItem OfferItemID="OFFERITEM-2880184804">
<TotalPriceDetail>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">48.00</SimpleCurrencyPrice>
</TotalAmount>
</TotalPriceDetail>
<Service ServiceID="SV_FLT001_PX003">
<PassengerRefs>PX003</PassengerRefs>
<ServiceRef>SD_ES</ServiceRef>
<FlightRefs>FLT001</FlightRefs>
</Service>
<FareDetail>
<PassengerRefs>PX003</PassengerRefs>
<Price>
<TotalAmount>
<SimpleCurrencyPrice Code="USD">48.00</SimpleCurrencyPrice>
</TotalAmount>
<BaseAmount xsi:type="SimpleCurrencyPriceType" Code="USD">34.00</BaseAmount>
<Taxes>
<Total Code="USD">14.00</Total>
</Taxes>
</Price>
</FareDetail>
</OfferItem>
</Offer>
</AirlineOffers>