If you're actually using curl... Couple tips:
1. Install the `jo` and `jq` packages as that helps with the JSON. "jo" parse RouterOS-style variables into JSON. And "jq" is useful on the results to pull out any data need. On MacOS with brew, it's "brew install jo jq", and most linux/WSL something like "apt install jo jq". Check the manage (or Google), lots of examples on using them and helpful with "curl".
2. There is a "--json" option in the most recent curl that avoid the need for the -H "content-type"... stuff
So the above can be shorten to using the above with --json, the "jo" tool (e.g. backtick ` runs a command within a command), and a couple shell variable makes curl way less painful...
ROSUSER=admin:password
ROSREST=https://192.168.88.1:443/rest
curl -X POST -u $ROSUSER $ROSREST/interface/ethernet/monitor --json `jo numbers="*1" once="true" ".proplist"="name,status"`
Since "jo" largely follows the same rules a RouterOS script, it's quite useful to cut-and-paste a command into curl – instead of dealing with JSON conversion yourself. See
https://jpmens.net/2016/03/05/a-shell-c ... e-json-jo/
"jq" is more complex topic, but if want to use some data from RouterOS, it makes quick work of pulling out a value for the shell from the JSON return. See
https://stedolan.github.io/jq/