Instagram and Facebook advertising is handled through Facebook Ads. So, you will need to share access through Facebook Business Manager. By doing this it will include running ads that use your Instagram account to represent your business and also boosting posts in your Instagram feed. To begin this, the Facebook page that you have linked with your company Instagram account needs to be added to your Facebook Business Manager account. Business Settings > Accounts > Pages Here is how the Ellie Brands page appears in our Facebook Business Manager:
Now we need to link your business account with Ellie Brands (or other agency) in Facebook Business Manager. To do that Ellie Brands would provide you with their Facebook Business Manager ID that you plug in.Business Settings > Partners
Once you have set up EllieBrands as a Partner you will need to grant them full access as a "page admin". Business Settings > Accounts > Pages
Now that you have allowed Ellie Brands to be a page admin you will need to continue working in Facebook Business Manager to "assign assets". The two assets that you need to assign are the Instagram account and a Facebook ad account. This allows us to run Instagram ads using your ad account.Business Settings > Users > Partners You will select Ellie Brands here. Then, select Instagram accounts and click "assign assets". Once clicked a dialog box will appear to select the asset type. Choose Instagram accounts, and select the check box next to your Instagram business account.
Now that you have granted Ellie Brands access they will link your Facebook ad account with your Instagram account. Simple enough right?