Unable to migrate table using GORM

I created a Postgres database in superbase.com and wanted to connect it to my Golang project using GORM. But when I try to migrate the table, it throws an error.

#database.go

    package initializers
    
    import (
        "fmt"
        "log"
        "os"
    
        "gorm.io/driver/postgres"
        "gorm.io/gorm"
    )
    
    var DB *gorm.DB
    
    func ConnectToDB() {
        var err error
    
        dsn := os.Getenv("DB_URL")
    
        DB, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
    
        if err != nil {
            log.Fatal(DB, "Failed to connect to database")
        } else {
    
            fmt.Println(DB, "Database connection established successfully")
        }
    
    }

#migrate.go

    package main
    
    import (
        "GinGorm/initializers"
        "GinGorm/models"
    )
    
    func init() {
        initializers.LoadEnvVariables()
        initializers.ConnectToDB()
    }
    
    func main() {
        post := &models.Post{}
        initializers.DB.Debug().AutoMigrate(post)
    
    }

Error thrown on command: go run migrate/migrate.go

&{0xc0001ce480 0 0xc00005f6c0 1} Database connection established successfully panic: runtime error: invalid memory address or nil pointer dereference [signal 0xc0000005 code=0x0 addr=0x28 pc=0xc19372]

goroutine 1 [running]: gorm.io/gorm.(*DB).getInstance(0x70?) C:/Users/harsh/go/pkg/mod/gorm.io/gorm@v1.25.12/gorm.go:406 +0x12 gorm.io/gorm.(*DB).Debug(0x0) C:/Users/harsh/go/pkg/mod/gorm.io/gorm@v1.25.12/gorm.go:329 +0x18 main.main() D:/Code/Go/gin/GinGorm/migrate/migrate.go:15 +0x2e exit status 2

The failure is in the Debug call. initializers.DB is invalid. It was never initialized.

The problem is here...

    DB, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})

DB, err := declares local DB and err variables. This local DB is masking your global var DB *gorm.DB.

Instead, declare just the err and use =

    var err error
    DB, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})

Here's a demonstration of the difference.