Fatal error after upgrading to PHP 8

After upgrading to PHP 8, when a user submits the form, the entry is created, but an error is displayed when trying to view the PDF. Here’s the error:

[23-Feb-2023 16:34:53 UTC] PHP Fatal error:  Uncaught Error: Undefined constant "street" in /home/dp/public_html/wp-content/uploads/PDF_EXTENDED_TEMPLATES/employment_application.php:89
Stack trace:
#0 /home/dp/public_html/wp-content/plugins/gravity-forms-pdf-extended/src/Helper/Helper_PDF.php(860): include()
#1 /home/dp/public_html/wp-content/plugins/gravity-forms-pdf-extended/src/Helper/Helper_PDF.php(262): GFPDF\Helper\Helper_PDF->load_html(Array)
#2 /home/dp/public_html/wp-content/plugins/gravity-forms-pdf-extended/src/View/View_PDF.php(217): GFPDF\Helper\Helper_PDF->render_html(Array)
#3 /home/dp/public_html/wp-content/plugins/gravity-forms-pdf-extended/src/Model/Model_PDF.php(241): GFPDF\View\View_PDF->generate_pdf(Array, Array)
#4 /home/dp/public_html/wp-content/plugins/gravity-forms-pdf-extended/src/Controller/Controller_PDF.php(243): GFPDF\Model\Model_PDF->process_pdf('5ac7b075931cc', 11374, 'view')
#5 /home/dp/public_html/wp-includes/class-wp-hook.php(308): GFPDF\Controller\Controller_PDF->process_pdf_endpoint(Object(WP))
#6 /home/dp/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array)
#7 /home/dp/public_html/wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#8 /home/dp/public_html/wp-includes/class-wp.php(399): do_action_ref_array('parse_request', Array)
#9 /home/dp/public_html/wp-includes/class-wp.php(780): WP->parse_request('')
#10 /home/dp/public_html/wp-includes/functions.php(1332): WP->main('')
#11 /home/dp/public_html/wp-blog-header.php(16): wp()
#12 /home/dp/public_html/index.php(17): require('/home/dp/public...')
#13 {main}
  thrown in /home/dp/public_html/wp-content/uploads/PDF_EXTENDED_TEMPLATES/employment_application.php on line 89

Rolling back to PHP 7.4 fixes it.