Packaging a set of 3 via FBA

I’m a new seller and watching the Seller University videos and am a bit confused on one point.

The item I am selling is a set of 3 toys. Since they are different items as a set, I know that I need to package them together and mark them as part of a set.

Part of the video says “units that aren’t contained in secure packaging, like loose sleeves or pouches, must be bagged or secured with a non-adhesive band or removable tape” (the video used a loose USB stick as an example).

I’m confused whether this applies to me or not? I was thinking of packing the 3 toys in either a die cut box or a bubble mailer – both of which would be permanently sealed.