Yes, you can request the writer to be in favor of a specific product or service, to highlight the pros over another type of product or service, a way of thinking, etc. You can also request a neutral opinion, only using facts and information.
If it is something that can lead to controversy, or that has different approaches, we advise you to give the author some details so that they can write the contents to meet your needs. You can ask the writer to generate controversy on the topic or not, to open a debate on your page, etc.
If no instructions are provided, according to the topic the author will write a quality text enriching the content at their discretion.