No. One of the requirements that needs to be fulfilled in order to be able to operate as a lone worker is being the only person present on the premises. This means that you cannot meet with anyone else whether it be a customer/client or colleague.
For those who work in outdoor trades – particularly in property and building maintenance, gardening and horticulture - work can be undertaken as long as there is no contact with other individuals, whether colleagues, customers or clients. For example, for a gardener, this would mean that members of the household need to stay inside the premises while the gardener works outside. More info here: https://covid19.gov.gg/faqs/lone-workers/can-i-work-if-i-am-lone-gardener and here: https://covid19.gov.gg/faqs/lone-workers/can-i-work-if-i-am-lone-window-cleaner-or-working-external-areas-house-example