IMap

You can access (change) the IMAP account password from iPad Settings.

For iOS12 and earlier:

Settings > Passwords & Accounts > [Your email account] > [Account] > [Incoming Mail Server] Password

The corresponding SMTP server Password can be accessed here:

Settings > Passwords & Accounts > [Your email account] > [Account] > SMTP > [Primary Server] > Password

Note, you can only set/change the IMAP/SMTP password - not view the already configured password(s).

Many [if not most] email providers - where Password Authentication is utilised - will use the same Password for both IMAP/POP3 and SMTP servers.

Many providers will use the same password for account access and email.

Be aware that some email providers, such as Google Mail, may use something other than Password Authentication (such as Token or OAuth). In such cases, Password Authentication may be optionally supported, but may require set-up of an App-specific password, per device, via the providers account administration web pages.