What is the meaning of 'skrt'?

While there is some dispute, it appears to be an onomatopoeic word, relating to the sound of car tyres when setting off rapidly or drifting; hence implying the ownership of an expensive car.

e.g. from the song "Skrt" by Kodak Black (2016)

Stick and move, then I SKRT, SKRT, SKRT SKRT, SKRT (Ooh I'm gone)
....
SKRT, SKRT, SKRT, SKRT, SKRT Jump in that Jag, SKRT, SKRT, SKRT SKRT,
SKRT, SKRT, SKRT, SKRT

It is less clear in "Skrt Skrt" by Tory Lanez (2018). In this case "skrt" appears to be the contrasted with "stop", hence it could be assumed that it has been extended to mean to start up, or to get going.

'Cause I like freaking
You like sex on the weekend
Me, too, me, too
'Cause I like drinking
You looking at me winking
Me, too, me, too
So give me the work
So give me the work
You gon' make me skrt skrt
You gon' make me stop stop
So give me the work
So give me the work
You gon' make me skrt skrt
You gon' make me stop stop

A discussion on reddit (OK, not the most reliable of sources, but it does reflect a wider understanding), includes the following definitions:

• I believe it's the sound of drifting in a fast car
• Pulling up wildly on a ride so the wheels go SKKRRRRRT. Aka drifting.
• Its like when the tires squeal in a car, so saying it implies that you have a really fast, expensive car

Skrt is a reference to the sound tires make when burning out prior to leaving in a hurry. In the '90's a common phrase used was "I'm gonna Skrt Out!"

SKRT stands for Ski Kayak Ripaille Team.
—Acronym Finder

[It] is an important term in hip-hop, rap, and modern culture. Used by many rappers.

Nowadays, used as a slang word to express excitement and humor. Often used as "skrt skrt" with a minor voice crack.
—Urban Dictionary

This is an example:

[John]: "Check out my new car!"
[Melissa]: "Pretty [...]"
[John]: "skrt skrt"
—Urban Dictionary