Inside SharePoint online we have 2 lists Parent & Child lists>> the child list has a lookup field to the parent list.
Now the parent list has 8000++ items, as follow:-

so when we try to create a new child record >> i will get this error on the lookup field:-
This is a lookup column that displays data from another list that currently exceeds the List View Threshold defined by the administrator (5000).
as follow:-

any advice how we can eliminate/fix this error?