Checkout SVN with credentials in Jenkins pipeline?

You can use the Snippet Generator for General SCM step. This displays the familiar Subversion configuration options, and takes credentials as parameter as usual.

The Snippet Generator will produce a tad ugly representation of your parameter selections and looks something like this:

checkout([$class: 'SubversionSCM',           additionalCredentials: [],           excludedCommitMessages: '',           excludedRegions: '',           excludedRevprop: '',           excludedUsers: '',           filterChangelog: false,           ignoreDirPropChanges: false,           includedRegions: '',           locations: [[credentialsId: '34761a89-1402-47d7-96e2-aec22ffdc50b',                        depthOption: 'infinity',                        ignoreExternalsOption: true,                        local: 'cable_branch',                        remote: "https://trac.nci.org.au/svn/cable/branches/$SVN_BRANCH"]],           workspaceUpdater: [$class: 'UpdateUpdater']])

Notice that the remote section uses double quotes, so that the variable $SVN_BRANCH gets substituted correctly.

Just adding some screen shots for OltzU's answer:

Step 1:

Step 2: