Strap on American British informal
To fasten or affix to someone or something for keeping safe
Firefighters strapped on safety harness carefully before rushing in the flame on the third floor.
Jane always straps the seatbelt on whenever he is on the car.
We intended to go trekking, and for that reason, we had to strap on a secure line.
To secure or tie someone or something down (to something).
1. To protrude or stand upright.
2. To attach something to a high point on a vertical surface so that it may be viewed or displayed.
3. To lift and keep something aloft.
4. To rob someone or something with a gun or other weapons.
1. To tie someone or something by something; to attach something onto someone or something.
2. To bother someone with something disagreeable or problematic.
If you say that you lash someone/something/oneself to something, you mean that you fasten he/she/it to something.
The verb "strap" should be conjugated according to its tense.