Role assignment issue when creating and updating users

I am utilizing Spatie's Roles and Permissions package to manage user roles in my application. Following the package's instructions, I've configured my user model accordingly. Within the user creation form, I've included a select option for assigning different roles to users, allowing for the possibility of multiple roles per user. However, I'm encountering two issues: 1. When attempting to create a user, I encounter an error message stating: "Array to string conversion." 2. During the execution of a user seeder, where roles are assigned correctly, I'm able to successfully assign roles. However, when attempting to update the information of a seeded user by assigning them a new role, I encounter an error message stating: "SQLSTATE[42S22]: Column not found: 1054 Unknown column 'roles' in field list." How can I go about resolving these issues? Below is the form for your reference: