'often required to' is correct and usable in written English.
It is used to indicate that something is frequently demanded of the subject. For example: "Employees are often required to work long hours."
Such promises are often required to get approval to begin trials in the first place.
Debtors are often required to hold auctions for assets before completing a sale.
Club promoters are often required to follow 'company policy' by wearing the given uniform.
As they steadied themselves, Given was often required to hurl himself around.
Celebration is needed and enthusiasm is often required to satisfy the personal ego.
"Women are often required to be an ideal of some description: pretty or likeable or witty.
Surgery is often required to remove necrotic tissue, and amputation of gangrenous limbs is sometimes necessary.
Slaves there were often required to provide their own food, which they raised on provision grounds.
Even so, failing pupils are often required to repeat a year.
Affordable housing projects across the city, including Manhattan, are still often required to provide parking.
Containing the animal waste is often required to protect water quality.
