There are couple different ways to make a transaction on Bkper:
Text input

Insert date, description and the value, like the image above.
If you have any attachment, click to insert.
Then, press record.
The form

Insert the informations and choose/create the From (debit) and To (credit) accounts.
Press the post button.
Drag and Drop

Drag and drop (one or more files) into your book to create new entries
Learn more about Drag and Drop.
A book's email address is composed as follows bookid@books.bkper.com.
1. Send an email to your book to record a new entry.
2. The subject becomes a comment
3. The email body is the text input of the new entry.
4. One Email Attachment becomes an attachments on the new entry.

Note: - Send several attachment, and each attachment becomes a new entry.
- You can find the bookid in the URL of a book.
Learn more about Email.
Google Sheets
You can use the Bkper add-on for Google Sheets to record transactions from your Google Spreadsheets:

Learn more about the Bkper add-on for Google Sheets.
Bank Connections

You can connection your bank accounts to have transactions pulled from your banks automatically.
Learn more about Bank Connections.
Other methods
You can also record transactions using Zapier, Pluga, other automations or the Bkper API.