How can I add custom generated text to posts using text from tags?
Something like: [Post Title] + custom text + tags + custom text ....
Or is there a plugin which does this ?
There is no plugin for that... at least one plugin :)
Create custom fileds for your custom text. Install ACF plugin (advanced custom fields) from wordpress.org.
Now... create a field group with ACF and then create custom fileds inside that group for your custom text 1 and custom text 2. (Don't forget to assign field group to post and/or pages.)
inside page/post template to display your custom text 1 and custom text 2.
You can try to call tags with get the tag list
Finaly, you can call Title with
So... just place this snippet inside your template on place where you want to show your record:
You can change custom_text_1 and custom_text_2 with records of your choice, but they must to be the same as you create them inside ACF.
If you want to display your record inside content area of your post or page, you can use any another plugin which can help you to create [short code] for given snippet.