Drill in staircase railing for metal rods

[thisismeto]

Hey there! I'm working on renovations and such here on the farm, and it usually works out for the most part, but now I'm stuck!
I'm trying to attach metal rods from the railing to the steps, and I've tried numerous ways to drill into the "railing" (test piece) and just can't get it to work well🥴
I know there's an insane amount of knowledge here, so I thought I'd kindly ask for help since Googling hasn't yielded a smooth result (probably searched the wrong way).

Grateful for any little tip☺️

Best regards, Stefan

 

[Mats-S]

Your image link isn't working, maybe you can upload again so we can visually see what you're supposed to do

 

[thisismeto]

Your image link doesn't work, maybe you can upload again so we can visually see what you need to do

See if it works if I put it here as a comment ☺️