typo3 read configuration options in typoscript - typo3

Question

I've tried several approaches to read the configuration options of my plugin in typoscript, but none of them seem to work
ajax.30 = TEXT
ajax.30.value = {plugin.tx_parser.settings.numVar}
ajax.40 < {tx_parser.settings.numVar}
ajax.50 < {tx_parser.settings.numVar}
ajax.80 = TEXT
ajax.80.value = {options.numVar}
ajax.90 = TEXT
ajax.90.value = {settings.numVar}
Can anyone please explain me the syntax or post a link where it is explained; I can use ext_conf_template.txt explained here https://docs.typo3.org/m/typo3/reference-coreapi/master/en-us/ExtensionArchitecture/ConfigurationOptions/Index.html but I didn't get these options in typoscript.
All I want is to access (in typoscript) the configuration options of the following picture
If I browse Constants I don't see any of these options
If I add my plugin to the site I see some plugin options but none of them I wanted

Answer 1

You can use constants with this syntax in TypoScript setup or constants
var = {$plugin.tx_parser.settings.numVar}
So in your case:
ajax.30 = TEXT
ajax.30.value = {$plugin.tx_parser.settings.numVar}
See https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/UsingSetting/Constants.html
To assign an earlier declared setup value you would use the < (object copy) operator
ajax.30 = TEXT
ajax.30.value < plugin.tx_parser.settings.numVar
Here is an on overview of its syntax: https://docs.typo3.org/m/typo3/reference-coreapi/master/en-us/ApiOverview/TypoScriptSyntax/Syntax/TypoScriptSyntax.html
The difference between constants and setup is essential. You can check in the backend in the module Template -> Template browser - see https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/UsingSetting/Debugging.html