In a medium saucepan, heat strawberries, sugar, and lemon juice over medium heat, stirring until sugar is dissolved. Increase heat to medium-high, and bring mixture to a boil; whisk in pectin. Reduce heat, and simmer for 25 minutes, whisking occasionally.
Transfer mixture to a shallow heatproof bowl, and let cool to room temperature. Once cooled, whisk in Champagne. Refrigerate in an airtight container for up to 5 days.
Recipe by Louisiana Cookin' at https://louisianacookin.com/strawberries-champagne-cake/