Use Pubmed and your brain:

Structural Mapping of Mutations in Spike, RdRp and Orf3a Genes of SARS-CoV-2 in Influenza Like Illness (ILI) Patients https://www.mdpi.com/1999-4915/13/1/136

"We performed complete genome sequencing of SARS-CoV-2 isolated from 17 outpatient’s visiting ILI patients. RNA was extracted from nasopharyngeal swabs and then reverse transcribed into cDNA using the High-Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Baverly, MA, USA). Viral genomes were enriched from cDNA templates by PCR using a set of 58 pairs of overlapping primers designed to cover the entire SARS-CoV-2 genome. Amplified viral segments were then equally pooled and purified with the Qiaquick PCR purification kit (Qiagen, Germantown, MD, USA) before sequencing on the Illumina MiSeq instrument (Illumina, San Diego, CA, USA)."

Further:

Laboratory testing of SARS-CoV, MERS-CoV, and SARS-CoV-2 (2019-nCoV): Current status, challenges, and countermeasures https://pubmed.ncbi.nlm.nih.gov/32302058/

They describe the standard procedure for SARS-CoV-2:

• isolation
• cultivation
• sequencing

"For isolation and culture of virus, centrifuging samples to remove cellular debris, and then inoculating the supernatant on human airway epithelial cells, Vero E6 cells or Huh-7 cells. It took about 96 hours for SARS-CoV-2 to be successfully cultured in human airway epithelial cells, and took about 6 days to be cultured in Vero E6 or Huh-7 cells."