as an action, you summon a wall of fire that spans 5 feet by 20 feet and is 10 feet tall,  you can summon it at any point within 45 feet except when said space is occupied. any creature that travels through the wall must make a con save with a DC of 8+ your spell-casting modifier, if they fail, they take 2d8 fire damage and cannot pass through it, if they succeed, they take half damage and can pass through. this wall lasts until the next round. if a projectile travels through the wall, a d20 is rolled, if the roll is higher than the wall's dc, it travels through and deals and extra 1d4 fire damage, if it fails, the projectile is destroyed. projectiles rules don't apply to hitscan attacks