Store the value of output inserted._ID to local variable to reuse it in another query

IDENTITY COLUMN

If it is an identity column and you are only inserting a single row then you can use SCOPE_IDENTITY() function to get the last generated Identity value within the scope of the current session.

DECLARE @NewValue INT;
insert into V_Post 
values('Please return the id of THIS row :)')
SET @NewValue = SCOPE_IDENTITY()

IF NOT IDENTITY Column Or Multiple Identity values

If it is an identity column and you are inserting multiple rows and want to return all the newly inserted Identity values, or it is not an identity column but you need the last inserted value then you can make sure of OUTPUT command to get the newly inserted values.

DECLARE @tbl TABLE (Col1 DataType)
DECLARE @NewValue Datatype;

insert into V_Post 
output inserted._ID INTO @tbl
values('Please return the id of THIS row :)')

SELECT @NewValue = Col1 FROM @tbl