1. Create a Supabase Account:
   Head over to the Supabase website and sign up for an account.

2. Create a New Project:
   Once you're logged in, start a new project. This will give you a unique API URL and API Key.

3. Install Supabase Client Library:

```bash
npm install @supabase/supabase-js
```

1. Import and Instantiate Supabase Client:
   ```javascript
   import { createClient } from '@supabase/supabase-js';

   const supabaseUrl = 'https://xyzcompany.supabase.co'; // Swap this with your Supabase URL
   const supabaseKey = 'public-anon-key'; // Swap this with your Supabase Key

   const supabase = createClient(supabaseUrl, supabaseKey);
   ```

1. Begin the Transaction:
   To kick off a transaction, use a begin block.
   ```javascript
   const { data, error } = await supabase.rpc('begin');
   if (error) console.error('Error starting transaction:', error);
   ```

2. Include Multiple Database Operations:
   Run the transactional operations you need within a try-catch block.
   ```javascript
   try {
   await supabase.from('table1').insert([{ column1: 'value1' }]);
   await supabase.from('table2').update({ column2: 'value2' }).eq('id', 1);
   } catch (error) {
   console.error('Transaction operation failed:', error);
   await supabase.rpc('rollback');
   }
   ```

1. Commit the Transaction:
   If everything goes smoothly, commit the transaction.
   ```javascript
   const { commitData, commitError } = await supabase.rpc('commit');
   if (commitError) console.error('Error committing transaction:', commitError);
   ```

2. Rollback the Transaction:
   If something goes wrong, rollback the transaction to keep the database clean.
   ```javascript
   const { rollbackData, rollbackError } = await supabase.rpc('rollback');
   if (rollbackError) console.error('Error rolling back transaction:', rollbackError);
   ```

1. Error Logging:
   Log the error details to a monitoring service or just the console for debugging.
   ```javascript
   console.error('Transaction error details:', errorDetails);
   ```

2. User Notifications:
   Let users know if something went wrong during the transaction.
   ```javascript
   if (rollbackError) {
   alert('An error occurred and changes have been rolled back.');
   } else {
   alert('Transaction successfully completed.');
   }
   ```