filemtime in template?

[ipbfuck]

Hi! i've this in my template to put og image in socialnetwork, and this image will be refreshed via cron every 24hrs.

<meta property="og:image" content="https://laltroweb.it/_script/thumbgen/_thumbnails/th_https_laltroweb_it.jpg">

 

how i can put a filemtime in template (then, to refresh in social network cache)?

i've try with php and double brackets, but i receive errors :/

 

<meta property="og:image" content="https://laltroweb.it/_script/thumbgen/_thumbnails/th_https_laltroweb_it.jpg?{{filemtime('https://laltroweb.it/_script/thumbgen/_thumbnails/th_https_laltroweb_it.jpg');}}">

 

thanks in advance,

S.N.