How to handle dynamic data in a script tag in head section for every page

I am absolutely new to Magento 2 (1 week in). I am trying to develop a Magento module that lets the admin specify a string (token) and when the admin saves the module I would like the token to inserted together with a <script> tag into the <head> section of each page.

If the admin changes the token and saves the config, it would be nice if it can update the same <script> tag. Or even remove it if no token is specified.

The module UI is no problem and also the saving works fine and intercepting the token value (with PHP), but I got stuck on how exactly to control the that gets inserted.

I experimented with view/frontend/layout/default.xml and can influence the header, but this seems to be very static.

<?xml version="1.0" ?> <page xmlns:xsi="" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd"> <head> <script src="" data-token="token_value" src_type="url"></script> </head> </page>

So basically I would like to change the value in data-token ("token_value") when the admin saves the config from the module, which I do from a Plugin\Config file:

... public function aroundSave(\Magento\Config\Model\Config $subject, callable $proceed) { // your custom logic $section = $subject->getSection(); $returnValue = $proceed(); $newConfigs = $this->scopeConfig->getValue($section); $token = $newConfigs["general"]["token_value"]; // +++ here would like to write value of $token to the <script> tag +++ return $returnValue; } ...

Any help appreciated!

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