The problem with the website code

Hello, I have a problem with my website https://doradnik.pl/. On the homepage, instead of articles, some code is displayed:

[td_block_3 category_id=”730″ limit=”4″ custom_title=”Meble do domu i do ogrodu” header_text_color=”#000000″][td_block_3 category_id=”729″ limit=”4″ custom_title=”Oświetlenie zewnętrzei wewnętrzne” header_text_color=”#000000″ header_color=”#38f916″][td_block_3 category_id=”702″ limit=”4″ custom_title=”Polecane materiały budowlane” header_color=”#2aff00″ header_text_color=”#3f3f3f”][td_block_3 limit=”4″ category_id=”713″ custom_title=”Polecane narzędzia i elektronarzędzia budowlane” header_color=”#eeee22″ block_template_id=”” header_text_color=”#000000″ review_source=””][td_block_15 modules_category=”image” modules_on_row=”eyJhbGwiOiI1MCUiLCJsYW5kc2NhcGUiOiIxMDAlIn0=” modules_category1=”image” show_cat2=”none” show_com2=”none” show_author2=”none” columns=”eyJhbGwiOiI1MCUiLCJwaG9uZSI6IjEwMCUifQ==” columns_gap=”eyJsYW5kc2NhcGUiOiI0MCIsInBvcnRyYWl0IjoiMjAifQ==” image_width2=”eyJwb3J0cmFpdCI6IjM1In0=” custom_title=”Najnowsze” header_color=”#f9c100″ header_text_color=”#000000″ td_ajax_filter_type=”” ajax_pagination=”next_prev” sort=”” image_size2=”” f_header_font_transform=”uppercase” category_id=”” td_ajax_filter_ids=”” show_review2=”none” show_audio2=”none” f_ex1_font_size=”eyJwb3J0cmFpdCI6IjExIn0=” f_ex1_font_line_height=”eyJwb3J0cmFpdCI6IjEuNiJ9″ modules_space2=”eyJhbGwiOiIyNiIsInBvcnRyYWl0IjoiMjAifQ==” modules_space1=”eyJhbGwiOiIwIiwicGhvbmUiOiIyMSJ9″ meta_padding2=”eyJwb3J0cmFpdCI6IjAgMCAwIDEzcHgifQ==” video_icon2=”24″ image_size=”td_485x360″ limit=”12″]

I checked the theme editing section in the header because I wanted to inspect the H1 headings, as there are two H1 headings set on the page. I didn’t make any changes, I just took a look. How can I fix this problem?I restored a backup from the previous day, but it didn’t help. The code is only visible in the Firefox browser.