Zend certified PHP/Magento developer

Magento 2.4.6. Unable to save the token in the database

My situation:

I created a new token_table (with InstallSchema.php) to store the token that will be needed when sending an API request to my endpoint.

Now I managed to create a form where admin user can enter the token and save it.

But after clicking on the “Save” button I get the following:

enter image description here

Can anyone suggest what the problem might be?

appcodeDevRestApiBlockAdminhtmlTokenEditForm.php

<?php

namespace DevRestApiBlockAdminhtmlTokenEdit;

use MagentoBackendBlockWidgetFormGeneric;

class Form extends Generic
{
    protected function _prepareForm()
    {
        $form = $this->_formFactory->create(
            [
                'data' => [
                    'id' => 'edit_form',
                    'action' => $this->getUrl('*/*/save'),
                    'method' => 'post'
                ],
            ]
        );

        $fieldset = $form->addFieldset(
            'base_fieldset',
            ['legend' => __('Token Information')]
        );

        $fieldset->addField(
            'token',
            'text',
            [
                'name' => 'token',
                'label' => __('Token'),
                'title' => __('Token'),
                'required' => true,
            ]
        );

        $form->setUseContainer(true);
        $this->setForm($form);

        return parent::_prepareForm();
    }
}

appcodeDevRestApiControllerAdminhtmlTokenSave.php

<?php


namespace DevRestApiControllerAdminhtmlToken;

use MagentoBackendAppAction;
use DevRestApiModelTokenFactory;

class Save extends Action
{
    protected $tokenFactory;

    public function __construct(
        ActionContext $context,
        TokenFactory $tokenFactory
    ) {
        parent::__construct($context);
        $this->tokenFactory = $tokenFactory;
    }

    public function execute()
    {
        $data = $this->getRequest()->getPostValue();

        if ($data) {
            try {
                $tokenModel = $this->tokenFactory->create();
                $tokenModel->setData($data);
                $tokenModel->save();

                $this->messageManager->addSuccessMessage(__('Token has been saved.'));
                $this->_redirect('*/*/index');
                return;
            } catch (Exception $e) {
                $this->messageManager->addErrorMessage($e->getMessage());
            }
        }

        $this->_redirect('*/*/index');
    }
}

appcodeDevRestApiviewadminhtmllayoutdev_controller_index.xml

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <referenceBlock name="page.title">
        <action method="setPageTitle">
            <argument name="title" xsi:type="string">Module</argument>
        </action>
    </referenceBlock>
    <body>
        <referenceContainer name="content">
            <block class="DevRestApiBlockAdminhtmlTokenEdit" name="token_edit" />
        </referenceContainer>
    </body>
</page>