Hi Partner,
May I know that why you need to clear lookup value using Xrm.WebApi?
"Xrm.WebApi.online.executeMultiple" is usually used to execute many actions like CRUD, functions in other libraries or other actions.
If you want to clear a field, here are the two situations.
1.This JS code is running in the entity form which contains the lookup field, in this case, you could use formContext.getAttribute().setValue() to clear the field value.
https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference/attributes/setvalue
2.This JS code is running in the entity form which does not contain the lookup field, if there are relationships between the 2 entities, you should get the related record is first by the look field first and then use webapi.updateRecord to clear its look up field.
For example, I want to clear lookup field A on account form but my JS code will run on Contact form, So I need to get the account id first from contact form by "CompanyName" and then use the accountid to update itself.
https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference/xrm-webapi/updaterecord
3.This JS code will be triggered by custom ribbons, as the above, you need to get the record id first by retrieveRecord with filter conditions and then use webapi.updateRecord to update it.
Regards,
Leo
