After upgrading the London theme from Joomla 3 to Joomla 4, my contact page is one total error message

How can I fix this ?
Notice: Undefined property: Joomla\Component\Contact\Site\View\Contact\HtmlView::$contact in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 22
Notice: Trying to get property 'name' of non-object in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 22
Notice: Undefined property: Joomla\Component\Contact\Site\View\Contact\HtmlView::$contact in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 74
Notice: Trying to get property 'image' of non-object in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 74
Notice: Undefined property: Joomla\Component\Contact\Site\View\Contact\HtmlView::$contact in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 80
Notice: Trying to get property 'con_position' of non-object in /public_html/templates/j51_london/html/com_contact/contact/default.php on line 80
Notice
: Undefined property: Joomla\Component\Contact\Site\View\Contact\HtmlView::$contact in
/public_html/templates/j51_london/html/com_contact/contact/default_address.php
on line
66
Notice
: Trying to get property 'email_to' of non-object in
/public_html/templates/j51_london/html/com_contact/contact/default_address.php
on line
66