Question: how to curl get and post

Hi,
Is there an example on how to curl get and post using LibCURL.jl?
For example is it possible to do:
```
curl "http://localhost:8000/echo"
```
Or
```
curl -H "Content-Type: application /json" --data '{"a":4,"b":5}' http//localhost:800/sum
```
The above example are directly taken from the following link (r package plumber):
https://www.rplumber.io/

Please note that I currently can't test the package HTTP because I currently can't install packages. I raise an issue in repo Pkg. The nice thing is that LibCURL comes pre-installed with Julia.
Thank you for your help.