Tenant in rent arears and not communicating

Access

We have a tenant that moved into the flat  in July 2023  and  is in arrears with her rent .We have issued a section 8 last month. Our letting agent has not had any communication from the tenant since November or been able to gain access to do a property inspection or carry out the gas safety inspection that was due at the end of January. She does not respond to emails ,her phone goes straight to voicemail.We have sent a letter by post,emailed and left a voice mail to inform her we are going to be doing a propert inspection next friday and to let us know if this date is not convenient .She has not responded . I know we cannot enter the property without her permission but what if something has happened to her ? Can we enter the flat if we are concerned for her welfare ? We are unable to see inside the flat from outside so would need to open the front door to check for any occupant .