SSRS Parameter help "Drop down or free text"

Hi Guys,
Need help. I created a SSRS report for the user to user(s) can insert or update records in the Config table.The First Parameter has to drop down option and values are "Insert, Update" What I want,
Step 1 = If user select INSERT, Next Parameter 2 should have free text to type the value
Step 2 = I‌F user select UPDATE, Next Parameter 2 should have a drop down values from.

I‌ got Step 2 and it is working but I need help with Step one. Any advice would be greatly appreciated.‌

be careful with free text. You could expose yourself to injection.

e.g. suppose the free text was (after the INSERT):

select top (0) 1; drop table yourtablename