ExtracText Admin configuration page can be reached from the "General Configuration" under Administration or using the URL <confluence-url>/plugins/servlet/extractext/admin . When you open the admin configuration page you will see any health check errors like license missing or similar. If there are are no errors then the plugin is working fine.
Maximum file size to process (MB)
This setting controls the maximum file size limit that ExtracText will process for extracting text. If file size exceeds this setting then the file will not be processed by ExtracText. The default value for this is set at 4MB. Note that there is Confluence setting for maximum file size as well. ExtracText setting is in addition to that. For example, If the maximum file size for attachments in Confluence is set to be 10MB and the ExtracText setting is set to be 4MB, then a file of size 5MB will not be processed by ExtracText. This setting helps to minimize load on server. For example if you upload a 8MB PDF file with 100 pages you may not want ExtracText to look through all 100 pages for finding images in them and extracting all those text. On the other hand if you have a system with adequate memory and processing power and you need the functionality you can increase this limit.
Select file types to extract text from and added to search index
This setting controls what file types are processed by ExtracText. For example if you would like to extract text from only PDF files you can disable other file types. By default all the file types are enabled.
Change language for text extraction:
This setting controls what language the text is going to be extracted in. The default setting is English.