there have been several questions about this situation: you are "invited" to publish your work in a journal - but you must submit your work to their "editing process". by the time they have finished with you, you are on the hook for considerable amounts of money.
everyone wants to point to a publication to say "they accepted my article".
stay with the reputable, established journals in your field. one article in a real journal is worth a hundred of the other.
i have been in writing, editing and publishing for almost 60 years. plenty of articles have been printed that were paid for by the person who wished to advertise - whether a product, a service, or her/himself. this type of article is called an advertorial. it is advertising that appears in the editorial pages of the publication, but it is advertising. many journalists will not write such articles as they are unfavourably viewed on one's resume.
this is what you are being asked to produce: advertorials. you pay the journal to publish your article. in effect you are buying space. a research article accepted by an actual journal carries a gravitas and authority those other journals cannot give it.
the industry sees what goes on: these publisher/journals etc are termed a vanity press.