I don't know. I'm quite disappointed right now. I've asked for the Web Clipper in the past I've even directly requested it of the developer but I never heard back from him.
Here is my solution that I use everyday that might work for you. It requires that you have the obsidian app installed but you don't have to use it you just have to have it set up to be able to use so that it will work with the obsidian Web Clipper.
The Firefox browser on Android supports extensions and obsidian has an extension for Firefox on android. I asked the Joplin developer if he would be willing to do something for Firefox on android but no response.
I frequently read Google news and sometimes want to clip a news article and put it into Joplin so this is my procedure.
In the Google News app I click the share button and choose to share it to Firefox where the obsidian Web Clipper is.
Once Firefox is running with the article in it I tap the menu button and then extension and then the obsidian Web Clipper. Once the obsidian Web Clipper is running it grabs the text for advanced it nicely into a document with a header.
This process also copies that new markdown document to the clipboard.
Then I open Joplin and paste from the clipboard to wherever I want the article to go.
I actually just installed an app called Macrodroid. According to Google Gemini this program is capable of automating this process for me I just need to learn how to do it.
I asked Gemini if it was capable of copying text from one app and then launching a second app having it converted into markdown and then paste it into a third app which will be Joplin. it claims that it will be able to do that if I can figure out how.
What I'm doing is a pain in the ass but I've gotten used to it.
I'm very curious about macrodroid and seeing if I am skilled enough to create a macro that can move text from one app manipulate in a second and then paste it into a third.
Hopefully this will stir up some interest and a kind developer will create a Firefox extension for Android Joplin. It can be an independent app too I don't care.
I'm also going to see if I can get the source code for the Firefox extension and convert it with AI into Joplin. Another option is to see if AI can create an extension based on the Web Clipper for desktop browsers.
It's an open wound.