need help! i cant see my submitted form..

Step 1 | Create a Database CollectionCreate a collection to store the information you receive through your user input elements.

Click Add on the left side of the Editor.Click Database.Click Create New Collection or Add to Site if it’s your first time.Choose one of the following options: Choose a Preset: Add pages with a collection already set up.Create a Collection: Create a custom database collection. Enter a name for your collection. Select Form Submission under the permission settings.Add fields in your collection for every piece of information you want your visitors to submit.

Step 2 | Add User Input ElementsOn a page on your site, add user input elements to create a form.

Click Add on the left side of the Editor.Click User Input. Click and drag the user input element you want to add.

Step 3 | Set Up Your ElementsSet up each element using its Settings panel.

Click Settings on each user input element. Click the drop-down under Type to select the type of info you want to receive. Enter your custom Placeholder text. Set the user input field to Required.
Note: Every user input element has its own Settings panel. Learn More

Step 4 | Add a DatasetAdd and set up a dataset to connect your page elements to your collection.

Click the Data icon on the left side of the Editor. Click the Add Data Elements tab.Click the Add icon next to the Form Dataset. This dataset is pre-configured to work with user input so you can collect data from your visitors. Click the dataset on your site.Click Settings to set up your dataset. Make sure the dataset mode is set to Write-only or Read & Write.

Step 5 | Connect Your Page ElementsAfter setting up your dataset, connect your elements to it.

Select an element in your form. Click the Connect to Data icon. Connect your element to the dataset added in step 4. Connect the element to a field in your Database Connection. Repeat these steps for each user input element in your custom form.
Note: If you are using radio buttons or dropdown list elements, click here to learn more about their connection settings.

Step 6 | Create a Submit ButtonAdd a Submit button and connect it to your dataset to allow users to submit their information to your collection.

Click Add on the left side of the Editor.Click Button.Drag the button you want to the relevant location.Click Change Text and change the text to Submit.Click the Connect to Data icon. Select Submit under the Click action connects to.(Optional) Click + Add success message. A text element is added to your page with a default message for your selection. You can keep the default text or edit the text to customize your message. (Optional) Click + Add failure message. A text element is added to your page with a default message for your selection. You can keep the default text or edit the text to customize your message. Under When successful, navigate to, the default is Stay on this page.You can also choose A link… to send users to another page after submission is complete.

I follow this step but i cant view it in my dashboard → Form Submission

Much easier if you just posted the link to the tutorial that you used.

You are looking in the wrong place.

If you are using your own custom user input form as in this tutorial shown here.
https://support.wix.com/en/article/creating-a-form-with-user-input-elements

Then all your submissions will be shown in the dataset that you created for that tutorial, this can be found under ‘Database’ in your Site Structure on the left hand side of your Wix Editor, although you might have to expand it to see that sidebar.
https://support.wix.com/en/article/corvid-working-with-the-site-structure-sidebar

Also note that this dataset has two collections, one is Sandbox and the other is Live, find out more about each version here.
https://support.wix.com/en/article/accessing-your-sandbox-and-live-database-collections

If you had used Wix Forms instead of crating your own user input form, then you will need to setup your Form Submission as shown here.
https://support.wix.com/en/article/creating-a-wix-forms-submissions-table