Get Guid lookup table from custome Field in Microsoft Project Online

Question

in this case i have custome field namely "Project Phase" then in value based on Lookup Table.

how can i get guid or internal name like 'Entry_d4399450ea69e61180cb00155d18530e' based on Delay value that appear in above image. this internal name i will use for updating data using C# Console.

here my simple code, but it doesn't VALID:

var PrjList = projContext.LoadQuery(projContext.CustomFields.Where(proj => proj.Name == cFieldName));
projContext.ExecuteQuery();
Guid pGuid = PrjList.First().Id;

Console.WriteLine(pGuid);

Answer 1

i finally i got simple linq query in ms project to get internal name of lookup based on custome field. here is my codeand it worked:

var InternalNameLookup = pubProj.CustomFields.LookupEntries.Where(x => x.FullValue == "Delay").First().InternalName;

this code will display internal name "Entry_d4399450ea69e61180cb00155d18530e". this is that i need to update my custome field based on lookup field.