It is required that the console that pops up at the bottom when "Open with other applications" can be opened from a third-party APP has its own APP options, click to jump to your own APP, and support file types by setting Document Types in the plist file, as shown below

Please note that our APP only supports Microsoft office file types, as well as pdf and txt. Referring to the UTIs corresponding to System-Declared Uniform Type Identifiers on Apple’s official website, only com.microsoft.word.doc was found. , but the document types in office include doc and docx. As shown in the figure, the setting does not support the docx type. I checked some information online and still can't figure it out.
I hope that the great God will give you some advice, and I would like to thank you