No, you do not need an Instagram account to advertise on Facebook. Facebook offers the option to create Instagram ads through your Facebook Business Page.
When creating a Facebook ad campaign, you can choose to have your ads displayed on Instagram as well. Facebook will use the information and content from your Facebook Business Page to create Instagram ads, allowing you to reach a larger audience without the need for a separate Instagram account.
Additionally, when you launch a campaign using UpHex, your campaigns are automatically set to launch on both Facebook and Instagram. This can save you time and effort while ensuring that your ads are reaching as many potential customers as possible.